Coz irl, and not the artificial benchies we have pre-3dmark08/whatever, the x2 wasn`t as good as is suggested or proposed.
Tis a good/great card, but to buy it when it only competes with a single 8800 GTX/Ultra isn`t ideal when u have a 8800GT, that similarly boasts to compete.
So in waiting for a 9800GTX, that, in all honesty, is the only real thing that is going to, without question, come out and beat hands-down a single 8800GTX/Ultra (without nailing urself down to old tech in the shape of a 9800GX2, which "should" be called a 8800GX2 tbh)
U have a 8800GT in one hand, and an x2 in the other that u can get ur cash back on.
U get ur cash back.
I personally wouldn`t get a new GTS, it would be the same as buying an x2 imo. GTX/Ultra is the only thing atm that u can buy and slap in ur case that isn`t going to have u reaching for the bank-card each time a pretender card comes out b4 the 9800GTX.