agreed on the video card, the GTS 250 is going to be faster (not by a whole lot, since its just a rebadged slightly faster clocked 9800GTX+ ) & still cheaper than the standard 9800GTX.
you've also got a Intel P45 ATI Crossfire capable motherboard, so unless you plan on running 2 ATI cards, or doing GPU processing with Folding@Home, and plan on using just one Nvidia card, no sense in grabbing a dual slot P45 really, which also do to the single card ties into the PSU, granted the Corsair 750TX is a good more reasonable wattage unit, its still more than you'll need for that setup.
unless you plan to run a Dual GPU card like the 4850x2, 4870x2 or GTX295. something smaller like a 600-650W PSU from Corsair or OCZ would be good.
Sound card, agreed to some extent on the sound card, well, agreed on all points actually, but also since your picking up 4GB of RAM is it safe to assume your planning on using Windows Vista 64 bit? (or XP 64-bit?), if so, its been a while, but I know Creative isn't/wasn't all that great with their Drivers even for 64bit windows. unless thats changed in recent past.
but for compatibility (not that thats really all that important with non-creative cards supporting OpenAL and all now, but all of those only support up to EAX 2.0) with their "defacto standard" EAX crap, a Creative X-fi chip is the way to go, for EAX 3,4 & 5.
also agreed on the i7 build, parts have come down some in the last few months, namely DDR3 RAM, to make things a bit more affordable, CPU's are still near the $300 mark to begin with. Motherboards still start just under or just over $200 range.
Changes to the above list with
Newegg.com - EVGA 512-P3-1150-TR GeForce GTS 250 512MB 256-bit GDDR3 PCI Express 2.0 x16 HDCP Ready SLI Supported Video Card - Desktop Graphics / Video Cards Newegg.com - Patriot 6GB (3 x 2GB) 240-Pin DDR3 SDRAM DDR3 1066 (PC3 8500) Triple Channel Kit Desktop Memory - Desktop Memory Newegg.com - ASUS P6T LGA 1366 Intel X58 ATX Intel Motherboard - Intel Motherboards (supports 3 card/3 GPU SLI though 4x on the 3rd slot might hinder a 3rd Nvidia GPU quite a bit, or 3 card/4 GPU Crossfire)
Newegg.com - Intel Core i7 920 Nehalem 2.66GHz 4 x 256KB L2 Cache 8MB L3 Cache LGA 1366 130W Quad-Core Processor - Processors - Desktops Newegg.com - ZEROtherm Core 92 92mm Nickel-plated Premium Cooler, Heat Pipe Direct Touch, Socket 1366 compatible - CPU Fans & Heatsinks (don't know how good this heatsink was but its one of the cheapest i7's out there so far, and given the choice of case, its the only one almost guaranteed to fit with little trouble, also uses the stock push pin design fasteners)
but minus the sound card, and using everything else from that list in your original post...
total comes to $1171.90 before any Mail in Rebate or adding shipping. ($45 in MIR's)
so leaves plenty of room to tweak the list, add a better CPU cooler, a sound card, good 5.1 or 7.1 speaker set or headset, etc.
though incase your in love with that case, might want to change it to something with better cooling/room for the i7 setup if you went with that.
Edit: dang Karma beat me to it revising the list
... though I picked some "Better" parts
some "less" better
also that mobo (Karma's pick) only supports Crossfire & not SLI, so might as well go with a ATI card if thats an issue for you. also if you add a 4th DDR3 stick, you lose Triple Channel Support & drops it to Dual Channel if the stick is the same as the other 3. (this was the board I looked at getting before I found my MSI Crossfire X58 on newegg for $150 Open Boxed)
hardware
prices 
Thanks for the advice, I guess I still have some changing around to do with my list.
I love it
