You don't need to read for hours. You should just go
HERE and see you'd have to get the 17" to properly run the whole studio -- especially Color. DVD Studio Pro should run on anything. It's a much older program but should get an overhaul in the next release
Long and short is Final Cut Pro itself should be fine on integrated chips like the Nvidia 9400M, however Motion and Color have much more stringent requirements (see below) and require discreet graphics. Compressor (and general renderings within Final Cut) are highly dependent on processor speed. The more powerful the computer (CPU and graphics card with memory) will allow for more real time effects and multiple streams. Firewire 800 is a must and best to run Raid Stripes with them.
So really decide what type of work you will honestly be doing. Is it high def, are you compressing hour long shows? Will you really use Color (it's extremely complex and you can do A LOT within Final Cut Pro) Motion? Will you do a lot of effects and color correction?
When FCS3 comes out, it will likely have higher requirements -- but again, only the higher end apps will need the dedicated graphics cards. Apple seems to be prepared to optimize the 9400M for a lot of their graphics work. I can't imagine the Macbook 'Pro' machines with the 9400 chips won't work with the new version. We'll see.
From Apple:
Motion-Specific Requirements
* A standard or built-to-order system configuration with a NVIDIA GeForce 5200, 6600, 6800, 7300, 7800, 8600, 8800 or Quadro class graphic card.
* A standard or built-to-order system configuration with a ATI Radeon 9600, 9700, 9800, X800, X1600, X1900, or X2600 class graphic card.
* For 16- and 32-bit rendering: a graphics card with at least 128MB of VRAM.
Color-Specific Requirements
* The standard graphics card in any Mac Pro, 17-inch MacBook Pro, 24-inch iMac, or 2.5GHZ or faster Power Mac G5 Quad.
* For 32-bit rendering: a graphics card with at least 256MB of VRAM.