I'm not going to race for first or anything, but I plan on getting my priest leveled asap. It really depends on when the expansions coming out - if it's while I'm in training at hospital, especially when there's night shifts (and really, I can't afford to be tired there. I might actually kill somebody :s) then I most likely have my BF multibox his shammy/druid and my priest to 90. I have 7 more characters at least to level 85-90, missing the quests won't hurt...
I'm also stockpiling stuff to sell for levelers as well as planned when to level which profession
But if the expansion comes out when I'm still on my summer holiday... I'll assemble a dungeon group of friends to get the people to chat with as well as a nice boost to leveling. Might even have a lan party if people are up to it This means lot's of coke (I know, too much sugar etc... But it's just must when having a lan), I'm most likely the one to take care that we have healthy food around (since my friends think they don't have to eat if there's something interesting going on or if they do eat, it's something like noodles and chocolate). And of course, decent rest before the stretch.