Here's a thought, as some of you have eluded to but not put together:
Nvidia has promised not to go into CPU production but stay in the GPU world,
Nvidia makes the most widely used Video Cards in the mass consumer market
Nvidia has recently unveiled it's Nforce in an attempt to merge GPU/Sound/Chipset
Nvidia keeps upping transistor and computational power on it's GPUs (especially the GF3)
I think those 2 billion is to research/develop fully integrated Chipsets, once it owns GPU/Sound/Chipset capability rolled into one, it has a chance to be a dominant player in 4 markes, not just 1 (GPU, Sound, Chipset, MOTHERBOARD).
Why? Look at the past aquasition of 3DFx, it was Nvidia's attempt to consolodate it's VERTICAL position in the GPU market. Look at the introduction of the Nforce and the upcoming Notebook version, it's Nvidia's attempt to break into 3 other existing and VERY LUCRATIVE markets and consolidate it's HORIZONTAL position.
In the end Nvidia can offer a cheaper (and in their hopes superior) combo: Video, Sound, Chipset, Mobo and the rest of the competition seperatley, WHICH EQUALS MARKETSHARE.
Now, why in the world would Nvidia want such integration? BECAUSE IT'S BEEN STARING EVERYONE IN THE FACE SINCE THE INTRODUCTION OF DECENT QUALITY ON BOARD SOUND AND LAN ON MOTHERBOARDS. Heh, and also the really neat reason that with it's own chipsets fully integrated, NVIDIA would be in a posision with it's GPU knowledge to offer it's own CPU alternative to either AMD/INTEL????? Why not? AMD is locked into CPUs, they subcontract out their chipsets to 3rd parties and they're strained by the pricing war with Intel. Intel on the other hand has no highend GPU knowledge, their video sucks but the rest is decent (JUST OVERPRICED) but revenues are hurt by the pricing war with AMD which at this point hold's Intel's attention as it's now a 70/30 split as opposed to the 80/20 or less reported a year ago.
WHERE DOES THIS LEAVE US???? While AMD and Intel choke each other and ATI and the 3rd party chipset busy playing on the Intel/AMD war, everyone is missing the point, NVIDIA has gone off on it's own and is more interested in helping everyone, including MICROSOFT (SEE THE TREND). In fact, it may already be too late for everyone else, that's why NVIDIA is just pulling more money out of the bank, to add some more distance to their lead
Just my thoughts, and besides history will have to be the judge.