If you want (dare?), you can guess how many 80s I have so far.
27
Too many, apparently. 
10!
and congrats!
The answer today, Boxing Day morning because I had to get up earlier than inclined, is: 26 on my WoW1 account, 32 total!
Holy heck! I got my TWW yesterday, will hopefully get to play some today. It will be nice to see the exp bar move again! Also hoping to get some dragonriding coins again, didn't get any for Zaralek but hoping TWW fixes that.
isle: One reason for this is the Mentor bonus - 5% permanent XP bonus for each of your first five 80s, maxing at 25%. Adding the stacked Anniversary bonus, it's been terribly advantageous.
wow, that's so impressive