Yeah, I've had to start playing on my superior "work" laptop.
The screen is smaller (14"), but because of its ridiculous specs, WoW runs smooth as hell, with only massive 40+ groups slowing it down just slightly.
Basically, a constant 60+ FPS in most environments.
Compared to my current laptop (19" w/Soundbar) which displays the game in a much higher resolution, but with far less FPS, and tends to lag a bit in raid environments or big groups in general.
Basically, somewhere between 15-30 FPS in most environments; if there isn't much going on, then it picks up a bit.
(The more crap on the screen, the worse it gets.)
Since my current laptop is pretty much on its last legs and I won't have my other laptop forever, I've been looking into building a desktop, but I've been putting it off for a long time now.
So I gotta get serious about that pretty soon.