We have more details on how the major mechanics changes are going to work for Mists of Pandaria and I like it more every time I find something new. The old style of talents is going away completely in favour of 6 talent choices. Each 15 levels you will get the option to pick one of three abilities and the choices are nearly all interesting utility options with very little to no raw output options available. I think this is a fantastic way to go. Ever since vanilla WOW players have been all taking the same choices and very rarely has there been much to play with in the trees if you want to maximize your performance. You take every passive +10% to this and +1% chance to that you can and some classes ended up with a few "Do whatever with this" points at the end and some didn't even have that. The new system looks like it will really give players tons of great options to customize their play. After looking at the various choices I was rarely able to decide quickly on what I wanted since few of the choices are really designed for one spec or the other. Nearly all of the choices looked appealing and they would certainly be worth changing around based on what encounters or situations you expected to face.
Of course some people were going with the line that there will always be one optimal build and everyone will just do that build but I don't buy that at all. Even today when specs on Elitist Jerks are very standardized there are still plenty of cases where the leftover utility points really are noted as "Up to personal preference" because it is hard to say which sorts of utility will be most useful. These abilities are carefully chosen so that there will often be a correct choice for a particular role in a particular fight but over the course of a week I can see great uses for nearly everything. I think we will actually see plenty of successful raiders that have no talent choices in common with raiders of exactly the same class and spec. This is a great change as I really don't see much value in putting one more talent point into "This attack does 5% more damage." every few levels as it really doesn't change gameplay at all. Adding something big and exciting every so often seems like a lot more fun.
This system of customization feels a lot more like Diablo 3 than current WOW. Making a few choices that really influence gameplay seems like a much better way to run talents than a huge number of choices that hardly affect gameplay at all. In Diablo 3 you need to pick a few defensive abilities, a few AOE abilities, a single target ability, a mobility ability and regeneration and utility abilities. You only get 6 choices though so you have a lot of tough choices to make but the number of different builds is immense. The new WOW is the same way in that even if 1 of your 3 choices at each tier is inferior you still have 2^6 = 64 distinct builds to work with. Lots of choices but each choice is very simple and discrete, there are absolutely no situations where you think "This choice is irrelevant". For a new player it is easy to get into because you just make a few choices where the effects are very obvious but the potential for an expert to maximize their abilities remains really large.
The addition of more difficulty levels in dungeons and raids is also welcome. I have talked before about how we need a Storymode setting for raids where people who just want to see the raid and do some low key fights can walk in and beat up some big baddies and now it will be there. This will make raiding accessible to casuals and people who don't like guild structure and is a great thing. Adding in a setting to let 5 man dungeons have really hard content is also fantastic, especially the feature that removes gear scaling from the equation. I like the idea of good players who are somewhat casual in playtime having really rough challenges they can attempt without having to round up a big group. Just like casual raiding this opens up opportunities for people to try things on a different schedule from what has been necessary in the past.
The more I read about Mists of Pandaria the more I think I might resub to WOW for it. The new race and class are fine, the mechanics changes and structure changes to the game are fantastic and all the details I have seen look really promising. I probably won't get back into the hardcore raiding mode I was in before but a group of people who want to run raids here and there and do 5 man challenges seems like something I could really get into. We will see how Diablo 3 is holding out when Mists of Pandaria launches!