Considering the success I had at predicting what patch 3.3 would force on the Wow playing community, lets see what I can do for Cataclysm.
Patch 3.3: My prediction that tanks and healers were going to be kings of the Dungeon Finder tool, was spot-on. On my battlegroup, I am experiencing almost insta-queues on my tanks, about 1-5minutes with Healers and did not even try to queue as DPS (through guild chat - it appeared to be 10-30minutes depending on time of day).
So my decision to respec some of my toons to tanks and heals - up my playtime vs sitting in dalaran waiting.
So Cataclysm... What impact will it have on playstyle?
I suspect the race up to max level (85) will dominate most players initially. But then the question on how master levels and the various paths work? I think these might "force" altoholics like myself, to focus on a single character or maximum 3 characters for development. Just gearing up is not going to be enough - you'll need to have certain role specific master level abilities as well.
However, playing alts is going to assist with guild leveling, far more than end-game raiding will (I think). But, until the mechanics of how guild level, and how members contribute are not explained in more detail, we can only guess and assume.
The reason why I think that alts will drive guild leveling, is that it is much easier to earn achievements on a low-level atls, vs a max-level character.. Aka there is much more un-explored achievements to get for a new toon vs a max-level.
My personal plans?
I definitely plan to roll a Worgen Warlock (my only class I have not played over level 20). I might even pay to get my druid race changed to a Worgen...
But getting atleast my paladin and priest to max level 1st will be my priorities. Instances and raid need to be tanked and healed :D
And I aim to capitalized on the shortage to maximize my playtime.