I emailed Alienware to ask them about the possibility of upgrading the m9750's video cards and this is the response I got:
"The Area 51m 9750 sports user upgradeable/replaceable video cards which are compatible with Nvidia's MXM specifications. However, at this time, I am unable to tell you if you will be able to upgrade the video card on this system (although there is a high probability that you will) because Nvidia is still working on their Geforce 8800 mobile video card.
As of this time, Nvidia has not released any specifications or requirements in regards to as to whether these new cards will work on existing platforms or if a new platform will need to be developed. Until then, we will need to wait until Nvidia releases this card and its specifications to see the possibility of an upgrade being offered."
I didn't even bother asking about Santa Rosa or anything else as I assume you will need a whole new mobo to upgrade the CPU from C2D to Santa Rosa, but I was wondering about the GPUs, and it looks like most 9750 owners will be able to upgrade to the mobile 8800s when nVidia realeases them. Maybe.