Maximum PC

I'm looking to build a budget gaming computer. Diablo 3 is my current concern but I'd like something that will last at least a couple years. I'm trying to stick to ~$500. Any suggestions or issues that you see with it I'd be very greatful to hear about.

BIOSTAR A780L3B AM3 AMD 760G Micro ATX AMD Motherboard ($45)
http://www.newegg.com/Product/Product.a ... 6813138329

Seagate Barracuda ST31000524AS 1TB 7200 RPM 32MB Cache SATA 6.0Gb/s 3.5" Internal Hard Drive -Bare Drive ($85)
http://www.newegg.com/Product/Product.a ... 6822148697

COOLER MASTER eXtreme Power Plus RS-550-PCAR-E3 550W ATX12V V2.3 SLI Ready CrossFire Ready Power Supply ($50)
http://www.newegg.com/Product/Product.a ... 6817171038

LITE-ON DVD Burner - Bulk 24X DVD+R 8X DVD+RW 12X DVD+R DL 24X DVD-R 6X DVD-RW 16X DVD-ROM 48X CD-R 32X CD-RW 48X CD-ROM Black SATA Model iHAS124-04 - OEM ($18)
http://www.newegg.com/Product/Product.a ... 6827106289

Rosewill FUTURE Gaming ATX Mid Tower Computer Case, come with Four Fans - 2 x Front Blue LED 120mm Fan, 1x Top 120mm Fan,1x Rear 120mm Fan, Support up to 6 Fans ($55)
http://www.newegg.com/Product/Product.a ... 6811147108

AMD Athlon II X3 455 Rana 3.3GHz Socket AM3 95W Triple-Core Desktop Processor ($80) ADX455WFGMBOXhttp://www.newegg.com/Prod ... 6819103911

G.SKILL Value Series 8GB (2 x 4GB) 240-Pin DDR3 SDRAM DDR3 1333 (PC3 10600) Desktop Memory Model F3-10600CL9D-8GBNT ($40)
http://www.newegg.com/Product/Product.a ... 6820231422

Sapphire AMD Radeon HD 6850 PCIE Video Card ($135)
http://www.amazon.com/Sapphire-Radeon-6 ... _res_rtr_1

I figure if I need to upgrade it in the future I'd get a new mobo, graphics card, cpu but try to hang on to the rest. I have a copy of windows 7 that will transition from my old computer to this one.

that will work, some of the things I would choose instead:

Rosewill Green Series RG530-S12 530W $42.50 with promo code (15% off) and free shipping, it's better unit than the CM in this case
Patriot Signature 8GB (2 x 4GB) 240-Pin DDR3 1600 (PC3 12800) $44 w/ free shipping and free 8GB Micro SDHC Flash Card w/ Adapter just in case you want to overclock a bit this will make it painless.

everything else looks good, cheers!