Imho, this is not a good time to buy a major computer component.
Due to holidays with a lot of people shopping for gifts, there is likely to be a shortage hence prices gettings jacked up. Also usually video cards with new technology is marketed in the first few months of a year so I would wait for the video cards vendors to come up with their new cards, you will have a ton of more selection, even if you decide to go with a slightly older card, they will likelt to be reduced due to the newer cards being available. Also since AMD took over ATI, next generation products from either company will likely to be more compatible with each other.

~TL

PS. Even though my current gaming system is decent enough, I am in the process of gathering parts to build my next system. I found a funky looking yet practical ATX case last Sunday at the computer swapmeet for $32 (no PSU as usual). I first decide on what type of a CPU I want and then the Hunt for Red Motherboard begins...then the RAM and finally Video, etc. at the very end depending on all the components and average/max power load, I will find the PSU....