Initially I thought that I was going to play off-spec healer for him while staying feral for our questing, however I soon found that the talent changes in Mists of Pandaria seem to have made that kind of thing pretty impossible. By the time we became eligible to queue for our first couple of dungeons, I still only had a single healing spell as feral - a heal over time at that - and my mana pool was limited to a piddly 200 or so, no matter how much int gear I put on. So I settled for queuing as dps.
Interestingly, our queues were still near instant almost all the time - with one notable exception when we just couldn't find any other damage dealers and spent about ten minutes waiting to fill the other two dps slots, which was probably more time than we then spent in the actual dungeon (Stormwind Stockade in this case). If anything, there seem to be too many healers in the low-level queue: in more than one run we ended up with a healer filling one of the dps slots. The holy pally in Wailing Caverns at least seemed to give ranged dps a pretty good go, but the disc priest/resto druid combo in Shadowfang Keep were both convinced that since they had both queued as healer, they didn't need to do anything but stand in the back and look pretty. (The druid literally had my pet tank on /follow for most of the run.) Since our third dps wasn't particularly on the ball either, this led to a rather odd experience where it felt like my tank and me were pretty much duoing the instance, while everyone else just tagged along to collect loot.
I suppose I mustn't complain too much though - at least we haven't run into any rude people... yet. For the most part, the players in our runs have been what you could call enigmatically silent, leaving their thoughts and motivations up to individual interpretation. Being a cynic, you could certainly interpret the fact that two dps dropped out of our Wailing Caverns run within the first five minutes as a sign that they were extremely impatient and even a minute of walking the wrong way (which we were doing at the time) was already too much of a waste of time for them to tolerate. For all I know though, they might have been some perfectly relaxed people who only just happened to remember at that time that they forgot to feed their cats.
Overall it seems to me that the "rush rush" culture is as alive as ever though. It's not that much of an issue in our case, as my tank is the sort of person who actually likes charging madly from one objective to the next, and I know that I can always tell him to stop if I need to. Gameplay-wise it's pretty dull from my point of view though, just running along, mashing my AoE buttons and collecting shinies along the way. I couldn't help feeling wistful in Blackfathom Deeps in particular, remembering how deadly so many of the trash pulls and boss encounters used to be, while it's now just a race to see who can round up the next room first.
One thing that mystifies me a little has been the loot. I suppose it's positive that we didn't encounter any ninjas, but I just couldn't shake the feeling that this was due to some sort of change to the loot system rather than people suddenly being more considerate. Most of the time I couldn't even see anyone but myself rolling (which among other things resulted in me winning four pieces of the "of the Fang" set in a single Wailing Caverns run), and I just can't believe that everyone was always passing on everything.
Not quite as I remember it...
Taken on its own merits, the most interesting instance so far has probably been Ragefire Chasm, because I had completely forgotten that Blizzard was going to redo that one for MoP. Imagine my surprise when upon entering I found mobs that looked like they escaped from the Firelands instead of a bunch of troggs! Now I'm curious to see what they've done to the Scarlet Monastery (which I know was redone).