minecraft will run without a glitch, unsure about guild wars as ive never had anything to do with it, and skyrim and bf3 should play above 40fps easily. the only thing i would change is to a nvidia for the physx but thats just me, the 7850 is still a good card
I don't see anything wrong with any of your parts. Your biggest graphical hit will be BF3. A 7850 should handle this fairly well. I am willing to guess at 1920x1080 60FPS you will run at around Medium settings with some of the other eye candy turned up or a few options on High. I'd set the game to AUTO and let it configure the settings for you, it's pretty good actually.
Do you already have these parts or are they on a wishlist of some kind? Just remember the GTX660Ti is coming out sometime next month. If you already have these parts, I can't really say anything negative about any of them. I have ALWAYS used ASUS motherboards and never had a single issue. They are almost always at the top or toward the top of any performance test. Corsair makes good RAM. That CPU is pretty much the Ivy Bridge chip you want to get if you intend to OC at all. I've also never had an issue with any Sapphire video card I've owned or for that matter anyone I know who's owned one.