i'd say go intel. the x38 chipsets are just coming out, and they're pretty hot, support the newest cpu's.
on the other hand, nvidia's 650i and 680i are very nice and worth getting. i love my evga 680i, just be warned that it's an enthusiast board, so you'd have to do some homework and replace some minor stuff (stock cooling and thermal material). BUT, the 750i and 780i are set to come out before year's end, and they'll support pci-e2 and DX10.1. the 6 series doesn't. but, aside from those 2 things, it doesn't look like the 7 series will be different from 6 series
for a graphics card, if you want balls to the wall performance, wait until mid december. nvidia's 9 series are coming out. they're switching from the 90nm gpu to the 65nm gpu. less power consumption, cooler running, higher performing pci-e2, DX10.1... if you're not a bleeding edge rider, i'd say get an evga 8800gt. lifetime warrenty and you can step up to a newer card if you do it within 90 days of purchase, and the GT's have 65nm gpu's in them. best of both worlds
for a power supply, i'd say get something by Ultra or PC&C if you plan to run massive graphics or sli. if you get an Ultra, get something in the 800+ wattage range... if you get a PC&C, get a custom piece from Performance-PCs.com, ... sleeve it and they will come
...they're a certified customizer for PC&C. manu. 5 year warrenty applies
for ram, get 1066mhz crucial. best stuff you can get
hard drives... seagate barracuda or WD aaks...