I have a Thinkpad W520 with both intel and nvidia graphics (via nvidia optimus). I very, very, rarely use the nvidia graphics card, and I think that if I were to buy it again, I would skip the extra card because of the extra hassle it brings.
The intel card is perfectly adequate for web browsing, programming, and even some light 3D things like the occasional google earth adventure. If you were to get a linux-optimized laptop with an nvidia card like the bonobo extreme, I would imagine that it would always use the nvidia card, which would severely cut battery life. Most of the time, I completely turn off my nvidia card to save power.
If you are thinking about getting a laptop designed for windows with nvidia optimus, be prepared to learn much more than you want to about the graphics systems. Since nvidia and the open source graphics community haven't been fully cooperating, getting things like extra monitors to work with optimus is very difficult on some models.
I am not aware of any programs running on my machine that use the GPU for non-graphics processing, except for research codes that I have occasionally been involved with.