The reason why I bought 2 X 5870s, and the reason why I spend absurd amounts of money on my computer is simple. It is my primary form of recreation at this point in time. You could say it's my work away from work. If you spend a lot of time with anything (be it your laptop, your car - if you deliver stuff), you want it to meet your needs exactly. To elaborate on the last point, I want to be able to sit down, pick up ANY game and never have a concern that I may have to adjust settings below maximum on a full HD resolution to increase the FPS above 60 or 100 (depending on the game). I like seeing all the cutting edge technologies at work, and I like being able to enable AA and AF, but I notice very quickly when the FPS of games isn't above 60 or 100. And it annoys me thoroughly when the game doesn't run smoothly with all details on max...
As to whether I'll buy this CPU, at this stage I don't have that amount of cash lying around. If I did, I wouldn't hesitate to upgrade to X58 and the cpu. Should I have enough money at some near-future point in time, I probably will upgrade...