A few thoughts....
If you're planning on future expansion, Intel is the way to go at the moment. You get a ASUS P-5K and it'll support the next generation of chips as well (due out later this year). The Conroe chips take less juice, give off less heat, and overclock to a larger %, and most at a cheaper price than comparative AMD chips.
An E6420 runs only about $180, an E6600 only about $222, and the ASUS mobo probably about $120-$130 or so (haven't checked, going from memory, and I may be wrong).
I'm not sure about the G.Skill quality, just make sure they've got heat spreaders. You've got a very high end system with lots of heat-creating devices. You'll want your RAM to 1) be able to withstand a bit more head and 2) be overclockable in the future.
I.E. If you get an E6800 (hypothetical) and run it at stock for 3 years, after that you might want to start overclocking to keep up with the "latest and greatest" and you won't want to replace the RAM because it doesn't overclock well.
Other thoughts: There are DVD-RW drives out there that cost less for the same features. You can usually find them in the $40 range. Why spend almost $70 for the same thing?
Unless you have surround sound, IMO you don't need a Xi-Fi. An Audigy2 is a lot less expensive for the same results (unless you REALLY work with sounds a lot and need to be able to hear the best quality when editing them). Also considerably less.
$130 for a case is also quite steep. Sometimes you have to (the way a case looks is important to me, as is how it functions). However, if it's going to be locked in a cabinet or under a desk invisible to your eyes, perhaps an uglier (cheaper) case?
And, my final thought: $600 is a huge wad of cash to lay down on a video card that still doesn't have decent drivers, and that still has a bunch of folks complaining about bugs, artifacts, mistakes, etc. Some have no problems. Some have lots. I wouldn't want to put that much green on something that may or may not work.
EDIT:
P.S. One last thought. If you have such a high-end system, are you going to keep your existing monitor/LCD, or use the $$ you have left to get a better one? Food for thought.
