There is one other thing you missed. Going from one video card company to another can be a real
bitch, unless you reformat. Unless you do that often anyway, then I guess it is fine.
The thing with the 4770 is that it is basically the 4850, except on a smaller manufacturing process (40nm). So basically it is a far more efficient version in terms of cooling and power usage. In a sense, it is like what happened with the
Jasper chip fr the 360.
But your first reason is exactly why you don't need to upgrade, and why I haven't upgraded either.
The 8 series cards (aside from Crysis) are good enough even today. The other thing is that you aren't likely to see a HUGE improvement from a 8800GT.
I don't know anything about the Radeon 4770 (or even my GeForce 8800 GTS mind you) so this might be unfair or totally false, but I have a suspicion that while the Radeon 4770 might do a great job running today's games for cheap, I will begin to struggle with future games at the same time my current card does.
Yes, the key word is at the same time, and that is correct. I just don't know when that time will come though.
For anyone interested, here is a review of the 4770:
http://www.anandtech.com/video/showdoc.aspx?i=3553So for a hundred bucks, it is a lot of bang for your buck. I won't say how future proof it is though, but it can certainly take anything from the current gen. It is more for those guys who have 6 or 7 series Nvidia cards, and have been out of the PC gaming loop for two years.