This is a bit off-topic, but I thought I'd throw this in for those contemplating dual ext. monitors w/ a MBP. You certainly don't have to wait for new laptops, Lion or Thunderbolt.
I've been using my 2006 MBP (15", 2ghz Duo, 2GB RAM) with dual monitors for over two years now.
The ATI 1600 w/256MB in my old laptop is more than enough to run the 1400x900 native display + two 1920x1080 22" Samsung monitors. I use a Matrox DualHead2Go to connect them. The driver essentially "fools" the GPU into thinking that there is just one big 3840x1080 monitor and then the Matrox breakout box divides the signal between the two monitors. Sure, I have to deal with the bezels, but I paid less than $500 for the whole rig two years ago for the ability to have my laptop drive a a three-screen 5,443,200 pixel workspace/desktop. For sake of comparison, that's more real estate than a MBP + a 27" Cinema display, or even a MBP + a 30" Cinema. Not as cool, but just as productive and 3x less than I would have paid for a big Apple display at the time I set it up. Ergonomically I think it's even better: I prefer the panorama of three horizontally aligned monitors vs, craning my neck up and down on one huge screen. My vertebrae swivel better than they flex!
I don't use my system for gaming or anything challenging for the GPU. I use it mostly for audio production in Logic, using one external monitor to arrange/edit the samples in a timeline and the other montior for displaying a 50+ channel mixer, leaving my laptop monitor for plug-ins, email & web.
If I were a gamer or pro graphic designer I wouldn't have done it this way, but for my application the system has been dynamite. YMMV, of course.