I recently worked my way through the old Onyxia attunement quest chain for the Horde. If you've never done it yourself, this series of "interactive movies" by Wowcrendor gives a pretty good impression of how tedious and annoying it is, gameplay-wise. Though I really liked getting to dress up as a black dragontaur, something that is not shown in the movie. These things have a pretty ridiculous waddle.
Now, while I definitely wouldn't consider this chain a fun attunement as a whole, I have to admit that the idea behind it, that you need to acquire a magical item to access Onyxia's Lair, rang very true for me. She's a powerful black dragon, but she's not stupid. She wouldn't let just about anyone wander into her lair unchecked, would she?
This in turn made me think about WOTLK's raid instances, and how I really feel that they are missing something in terms of story by not having any kind of attunement. The only WOTLK raid that does have one is Malygos' Lair, which requires you to get a key from Sapphiron in Naxx. Sapphiron used to be a mighty blue dragon in life, so I guess it makes sense that he would have something that allows access to the leader of the blue dragonflight. That's fair enough. If we look at any of the other raids however... oh dear.
First we have Naxxramas. What, does the Scourge really have no magical wards or anything that prevent people from just wandering in? Even worse, there's nothing in the game that even encourages you to go raid the place. The Alliance NPCs in Wintergarde Keep are chatting about the floating citadel and its inhabitants for a bit, but there are no quests telling you to go there or anything. The Horde has it even worse, because they don't even acknowledge its existence. I think I once saw a line of quest text that said something about the Alliance being under siege from Naxx, but that this was something that didn't concern the Horde. Seriously, the only reason to go there was the meta-game knowledge about it being Wrath's introductory raid. Poor storytelling, that.
Sartharion is even worse, as there is absolutely no explanation for why he is even there or why we should kill him. I believe that I read somewhere that Blizzard did have plans to include a story for him but it was cut out due to time constraints.
Then we have Ulduar. This one gets a pass from me because even though they are not required for being allowed to enter the instance, there are quests in the Storm Peaks that serve as a sort of introduction to the place. There was also this video on the official website. And the fact that anyone can just go inside can be explained by the fact that Brann has already kicked down the door.
Trial of the Crusader not requiring any kind of attunement on the other hand was terrible in terms of in-game logic at least. The whole point of the Argent Tournament was to put together an elite team of fighters to face the Lich King. That's why you go from aspirant to champion to crusader, proving yourself over and over again along the way. Yet anyone can enter Trial of the Champion and Trial of the Crusader, even if they haven't proven their skills at the tournament in any way? No, just no.
This logical error then continues in Icecrown Citadel. Yes, the Ashen Verdict have kicked down the door and made the place accessible, but again, wasn't the whole point of the Argent Tournament to make sure that only the ones with the highest chances of survival would enter ICC? Yet once again, they take absolutely anyone. This is in direct contradiction of a whole patch worth of story. Bad Blizzard, bad!
That said, I think we can all agree that story and gameplay can easily come into conflict, and what's good for one can be detrimental to the other. For example, requiring people to actually have the Crusader title before they could enter Trial of the Crusader would have been the harshest attunement ever, seeing how the title takes almost a month to acquire even if you do all your daily quests every day. Still, I don't think that excuses Blizzard from making a nonsensical story just to facilitate easy gameplay. For example, they simply could have given the Argent Tournament instances names independent of the titles, such as "The Grand Coliseum" or whatever; that alone would have alleviated a lot of the concerns mentioned above.
Lately I realised however, that attunements are important for more than just story. People have derided them in the past as being nothing but artificial obstacles to keep content exclusive, but I think that this expansion has proven that hardly anyone really wants everything to be equally accessible to everyone anyway.
Why do you think Blizzard released TotC's bosses one at a time and delayed the opening of ICC's different wings? Because they didn't want everyone to complete all the new content right away. Why didn't they just keep attunements then? They serve a similar purpose and at least they leave the ball in the player's court and give them something to do: "Okay, you can't go in there - yet. But you can complete a couple of tasks which will then open the place up. Go work on them!" In contrast, the gating that we saw in this expansion gives people nothing to do but sit on their arses and wait, because they have no way of influencing their access to the raid. Dead boring if you ask me - I'd take a long attunement chain over that any day.
More importantly though, the players themselves also have an interest in keeping people out of content if they aren't ready to cope with it yet. That's why you see all these silly pugs that require achievement linking and GearScore numbers. After all, Blizzard themselves have drilled it into our heads that gear is the only thing that matters. WOTLK heroic dungeons require no attunement - the dungeon finder will only check your gear. And what was the argument for rewarding top-tier emblems from heroic dungeons again? To allow people to get the gear to raid ICC - the implication being that that's all they need, actual experience with raiding or other group content is completely optional.
Good attunements on the other hand can be so much more useful for judging a player's readiness for content. I always thought the heroic Magister's Terrace attunement was brilliant - all it requires is that you do a quest while completing the instance on normal mode. That way any person who joined your heroic group was guaranteed to at least have a clue about the instance.
The Karazhan attunement was pretty good as well in my opinion - a bit lengthy maybe, but it required you to take an interest in the instance and to tackle some reasonably challenging content with a group - if you couldn't make it through normal Black Morass for example, you really had no business being in Karazhan yet.
The way I see it, the main problems with attunements in BC were that some of them were way too convoluted, and that they were very alt-unfriendly. These issues would have been relatively simple to solve though by making keys account-wide (maybe leaving the quests as something optional for alts) and generally easing up on the complexity. Blizzard was making good progress on the latter towards the end of BC, but then they threw the baby out with the bathwater in WOTLK when they just got rid of attunements altogether (with the exception of Malygos).
Unfortunately I haven't heard anything good about Cataclysm in that regard either. From what little I've heard it sounds like instances and heroics will once again have nothing but annoying gear checks - I remember hearing a story of someone who had to go quest before an instance run just to get a new ring, which had worse itemisation but a higher ilevel, just so the game would allow him to enter an instance.
I don't mind having to work to get to see all the content, but it should happen in a way that makes sense story-wise. Doing nothing but grind gear to get to the next tier is boring and creates an environment where people are judged by nothing but the numbers on their epics.