You have a great mobo and DDR3 isn't better than DDR2. You should better get a new AM3 CPU and wait for the new Intel sockets (the current ones will be replaced next year).
Your video card is very strong but if you want DX11 you can either get two HD 6870 or wait a little for the new HD 6950/6970/6990 scheduled this month, the HD 6970 will be the fastest single GPU card on the market, the HD 6990 will be the fastest video card.
I think that you should just wait for SB to come out. Which that is expected release sometime in Q1 2011 which is around January February time. The previewed performance looks fantastic and it's OCing ability really pwns the i7's of the current lineup. The SB i5 Line seems to rival the current i7 980X...
And if your thinking, oh I'll just buy a mobo now kind of thing if you plan to upgrade to SB. SB is going to be on an entirely new platform, of LGA 1155.
Also, if you don't want to wait for SB, just wait until the end of this month when Cayman releases (69xx) That'll have a great performance increase (if it follows AMD charts like the 68xx did). The expected performance is 20% over the 480 and probably (most likely) less power consumption than the 480 GTX. Plus we should expect great scaling since 68xx had the same.
Anyway, if you do stick with this decision. I suggest changing the mobo, as you don't need to spend 360$ on a mobo that's pretty much not worth the price they set on it. Even the Sabertooth X58 mobo can compete directly with the ROG line.
ASUS Sabertooth USB 3/Sata 6 X58: http://www.newegg.com/Product/Product.aspx?Item=N82E168...