laptop fried, going to try to build a desktop

[brokenlaptop]

So my laptop died and i decided to build a desktop cause i graduated form school and don't need a laptop anymore. my roommate has built a computer in the past so i think he can put it together but he hasn't kept up on components/prices in a few years so hes not much help. i spent a few hours on newegg and this is what i came up with, let me know what you think. (is everything compatible? are there similar/better components that can be had for the same or slightly higher price? my budget is a little flexible, around 6-700 dollars.)

I will be using this computer for:
-playing all the games that came out in the last few years i wasn't able to play (farcry, Crysis, CodMW, WoW, etc)
-basic internet/video/music multi-tasking, but mostly want the best value for playing todays games and upgrade potential to upgrade some components in the next year or so without having to buy a whole new pc.

Case (90.00):
LIAN LI K60B Black CECC Steel ATX Mid Tower Computer Case - Retail
http://www.newegg.com/Product/Produc...82E16811112247

PSU (45.00 after mail-in rebate):
OCZ Fatal1ty OCZ550FTY 550W ATX12V / EPS12V SLI Ready CrossFire Ready Modular Active PFC Power Supply
http://www.newegg.com/Product/Produc...82E16817341022

Motherboard (115.00 after mail-in rebate):
ASUS M4A78T-E AM3 AMD 790GX HDMI ATX AMD Motherboard
http://www.newegg.com/Product/Produc...82E16813131366

CPU (120.00):
AMD Phenom II X3 720 2.8GHz 3 x 512KB L2 Cache 6MB L3 Cache Socket AM3 95W Triple-Core Black Processor
http://www.newegg.com/Product/Produc...82E16813131366

Video Card (175.00):
ASUS EAH5770/2DIS/1GD5/V2 Radeon HD 5770 1GB 128-bit GDDR5 PCI Express 2.0 x16 HDCP Ready CrossFireX Support Video Card
http://www.newegg.com/Product/Produc...82E16814121355

RAM (92.00):
G.SKILL Ripjaws Series 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1333 (PC3 10666) Desktop Memory Model F3-10666CL8D-4GBRM
http://www.newegg.com/Product/Produc...82E16820231275

Optical Drive:
Spare DVD/RW

Hard Drive:
Handed-down 80GB 7200rpm HD
500 GB Lacie External Hard Drive

Newegg Price Total: 675.95

So thats what I've got, let me know what you think. also, what would the lifespan be of this system to play current games? 1, 2, 3 years?

Thanks

[pam123]

That's a pretty "future proof" build and should be good for the next 3 or 4 years, with a new video card somewhere in the middle of that, but I'm guessing the first upgrade will be the hard drive and I don't see where you've budgeted for a copy of Win7.