Pasho,
It depends on how much time you devote to it, I guess. I started WoW, and even factoring in a full time salaried job (so that's 40-50 hours a week) plus college (8 hours a week), a wife, housework, and homework, I still managed to get to 40 in WoW in one month. Granted, I was spending 99% of my actual free time playing, so that factored into it.
I'm playing EQ2 now, and after having the game around a month so far I'm level 19/11. I haven't been playing with 99% of my free time, though, I've had some other hobbies that I've been working on too.
Personally, I like a game that levels slower. I wasn't terribly fond of EQ1's slowness, but that was mainly because I started 3 years into the game, so there were already a bunch of people who had seen/done everything. One of the things I am enjoying about EQ2 is that although there's some high leveled people, they don't seem to be everywhere. The world is still one where there's things to discover, FAQ's that haven't been written, you know?
With an expansion already on the way, I should be nearly strong enough to participate in it by the time it's released. If not, I can just about guarantee that I'll be done with it by the time the next expansion releases, so that will work out nice for me to be able to experience all the new content, as opposed to EQ1 where I wasn't able to participate in 75% of the game even at level 31 or so.