Few things man,
1. There are no world first....you don't need to min/max, you will never be special, the content has been beaten before and nothing is going to change that.
2. Good luck with that, once the first wave of people come through and their all snatched up the pool will be low and you'll take whatever you can get, the old saying beggars can't be choosers and that's exactly how it will be just like in vanilla. If you think every priest is going to roll Dwarf for some stupid spell that you don't even need if you have a tank worth a lick, you're mistaken.
3. People are going to quit a lot and go back to other games or retail, again lowering that pool even more within the first few months. Time constraints, most that have been there before will burn out and want something new. There are always exceptions to the rule though...
4. 40 mans are hard to fill, look at live right now...people have a hard enough time with getting 20 people to show up night in and night out, you'll take what you can get.
5. Whatever you saw on the Private servers is a joke....I played Classic and at times we didn't even have a Dwarf Priest in the guild, of course we have a great tank that wasn't a baddie but we made it all the way to Naxx and even beat a few bosses doing 3 nights a week...not hardcore in the least.
I can't wait for the hardcore/Min/Max/e-peen crowd to come in, consume and then leave.... their a cancer to the community and they'll do nothing but turn others off and create an elitist mindset that's not healthy for anyone. If you're trying hard in Classic, you're doing it wrong...enjoy it this time around, stop thinking about being first or what's best and have a good time!
Play what you want! Don't let anyone scare you or try and tell you others won't let you into their raid groups unless you do X-Y and Z....Don't stand in fire, do your best, come prepared and you'll do great! =)