Even if they're not officially out yet, a chinese website broke the NDA and posted some benchmarks. Someone put them into one diagram, see this picture here. As we can see, they haven't included a 9600GT, but seeing the performance of a 3850 and knowing the 9600GT being in the same area of performance, we can conclude that they fit right between the 9500GT and 9600GT. That's a price range of $70 to $120. To make the cards attractive, ATI's partners would have to sell them for less than $90 to not make the 3850 obsolete.

So I think one can speculate that for a premium of $20 (over a 9500GT), one can get twice the performance soon Probably a good choice for a gamer on a budget.

Today, it was launched officially. The consensus from different reviews is: a solid competitor for the 9600GSO (i.e. 8800GS) at the same price point, slightly slower at low resolutions, faster with higher resolutions and AA. Price/performance slightly lower than a 9600GT. Uses a less power in idle, more under load where it also gets quite hot. It almost matches the speed of ATI's previous performance generation 3850. Ideal for decoding HD videos (better VC-1 support than nVidias offerings). All in all: a decent mainstream solution.