Approximate Purchase Date: (This summer! I can wait until Black Friday for cheaper prices and that time I can get better parts!)
Budget Range: $1200-$1500. Mail-in-Rebates would be nice, too!
System Usage from Most to Least Important: I like to watch 1080p videos, play hardcore and newest games with ultra settings without dropping frame rate.
Parts Not Required: (I will keep my HDD, Monitors, Keyboard, Speaker, and my current GPU (If possible))
Preferred Website(s) for Parts: NCIX, Amazon, Newegg, Frys (I may likely go to stores if the price is the same as online).
Country: I am living in US (Portland, OR).
Parts Preferences: by brand or type:
For CPU -> definitely Intel. Some people prefer i5-2500k over i7-2600k because it's cheaper and it's slower than the 2600k just a little bit. Who knows? I think I will go with i7.
For RAM: Corsair 16GB Vengeance at 1600 MHZ (The i7 only support 1333 Mhz); Is there way to get the Memory run at 1600 Mhz? No Overclocking for RAM.
If you're waiting until summer, then I'd advise you to go Ivy Bridge and HD 7xxx instead of Sandy Bridge and HD 6xxx. Not because the latter are bad components, but because at that point you'll get a better value from the former.
Neither the 2500k nor the 2600k officially "supports" DDR3 1600; it's technically an overclock in both cases, but don't be afraid of that. IB will officially support DDR3 1600, and overclocks hopefully in excess of 2133. If you're looking for gaming performance, I'd recommend going with the fastest 8GB kit you can get for under $100. I have no idea what this will be in 4-6 months, but the higher speed will provide you more benefit than higher capacity, though both are fairly negligible.
I'd get a motherboard like the one you have listed, but for IB. Dual GPU setups are the way to go, in my opinion. I'd go with a strong mid-high range card, probably the 7870/7950, and then double up down the road.