My desktop had a 7600 with 256 MB of dedicated memory, while the notebook I bought (the best I could find for under $2500), had a 7600 with 512 MB dedicated RAM.
I multitask-to-death on my desktop, with two monitors, a game running in full screen on one, IMs, web-browsing, music, videos, and even occasionally, a second game...on the other monitor. (Idle time.)
The desktop handled this with no constant lag problems, but the laptop, which had an additional gig of RAM, double the dedicated graphics RAM, (correction to earlier), the same 7200 drive, and the CPU was a 2.2 GHz dual-core versus my desktop's 2.0 GHz single-core, couldn't even run WoW by itself, without lagging slightly.
So, no, I was not using integrated graphics or anything low-end...as I said, the laptop was better in all aspects beyond whatever the limiting factor was... I honestly don't believe it's possible to have a good gaming laptop, at least, after gaming on a desktop for many years.
