Did I buy the wrong power supply?

Hi, I recently bought a 520w power supply by Corsair (I am not intending to make a commercial here), but now I am thinking that 520 watts is very low! I am no sure if I am wrong or not.

I've seen power comsumptions of an Core 2 Duo E6600 that I want to buy, and THG says that at full charge is 200w.

Then the motherboard, wich I am planning to be an ASUS Striker Extreme, from which I don't know the power consumption, but at least 8 watt.

I also want a GFX Nvidia 8800, that in the web site andandtech tells it consumes 270 ~ 300 watts depending of the manufacturer. If I plan to use SLI, then it will be from 540 to 600 watts.

Then imagine about 3 hard disks with 12w each, 32w

Then count the tower fans and the CPU cooler. Add to this the memory, the USB ports when used and I suppose that I am forgetting things.

So:

200 + 80 + 270 + 32 = 582 watts
200 + 80 + (270*2) + 32 = 652 watts with SLI

In any case my PSU will melt.

What I am missing?