gaming rig

so im trying to build a gaming rig that wont break my pockets. i currently have a build that will cost me around $1300 (this includes a monitor, the OS, and Keyboard). i want to be able to play World of Warcraft and do 10 and 25 man raids with NO lag and im also looking to play other games as well however im not looking to run anything hardcore like crysis.
this is my current build as of now:

GIGABYTE GA-P55A-UD3 LGA 1156 Intel P55 SATA 6Gb/s USB 3.0 ATX Intel Motherboard
http://www.newegg.com/Product/Product.aspx…N82E16813128412

XFX HD-587A-ZNF9 Radeon HD 5870 (Cypress XT) 1GB 256-bit GDDR5 PCI Express 2.0 x16 HDCP Ready CrossFire Supported Video Card w/ATI Eyefinity
http://www.newegg.com/Product/Product.aspx…N82E16814150443

XFX P1-650X-CAG9 650W ATX12V 2.2 / ESP12V 2.91 SLI Ready CrossFire Ready 80 PLUS BRONZE Certified Modular Active PFC Power Supply
http://www.newegg.com/Product/Product.aspx…N82E16817207002

Intel Core i5-750 Lynnfield 2.66GHz 8MB L3 Cache LGA 1156 95W Quad-Core Processor
http://www.newegg.com/Product/Product.aspx…N82E16819115215

G.SKILL Ripjaws Series 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Desktop Memory Model F3-12800CL9D-4GBRL
http://www.newegg.com/Product/Product.aspx…N82E16820231277

Western Digital Caviar Black WD1001FALS 1TB 7200 RPM 32MB Cache SATA 3.0Gb/s 3.5" Internal Hard Drive
http://www.newegg.com/Product/Product.aspx…N82E16822136284

this is the build i have now, i was wondering if this is a good build or if im over doing it with some of the stuff i've got up here (i've been known to over do alot of things).

any advice would be extremely helpful
thanx

Hey there, You say you don't want to play anything hardcore like Crysis, that spec would make mince meat out of Crysis! Well, Crysis is a hard game to run well (probably because it wasn't optimized properly in my humble opinion), but that kind of PC would EASILLY run WoW. 'Bob