Almost done... any glaring errors?

I've been doing some research into building a new computer with the indispensable help of this esteemed forum. I think I've got the right idea, but I'm a first-time builder and I might have messed up/forgotten something. I would greatly appreciate any corrections/feedback/comments.

Emphasis is on gaming.

There's a Micro Center nearby where I'll be making just about all of my purchases, unless Newegg has a really killer deal or something.

Case: Cooler Master HAF912
http://www.microcenter.com/single_product_results.phtml...

Mobo: ASRock Z77 Pro4 LGA 1155 ATX Intel
http://www.microcenter.com/single_product_results.phtml...

*I'm not very knowledgeable about motherboards. This one looks like it has everything I need at a good price. Thoughts?

PSU: Re-using my old one. It's a SeaSonic, 650W. Can fetch the link if needed.

*It has, however, seen pretty constant use since late 2008. Should I replace to be on the safe side?

CPU: i5 2500K
http://www.microcenter.com/single_product_results.phtml...

Memory: Corsair XMS3 8GB DDR3-1600
http://www.microcenter.com/single_product_results.phtml...

OS: Windows 7 Home Premium 64-bit

GPU: !UPDATED! EVGA GeForce GTX 560 ti
http://www.microcenter.com/single_product_results.phtml...

*I won't be running anything at resolutions higher than 1920x1080, and I can live without really high AA/AF/extras like DoF, motion blur, etc. This card's benchmarks seemed about right, can anyone confirm?

Monitor: Acer S231HL bid 23" LED Backlight Widescreen LCD
http://www.microcenter.com/single_product_results.phtml...

Hard Drive: !UPDATE!
120GB SSD
http://www.microcenter.com/single_product_results.phtml...

500GB Seagate Barracuda
http://www.microcenter.com/single_product_results.phtml...

Speakers, mouse/keyboard: Already taken care of.

My budget is $1000-$1200. So far, the listed components come to roughly $1100. I'm not intending to overclock just yet (it'll be an achievement if the thing boots successfully). Any thoughts?