Computer Games Online previews the TNT2 (thanks Billy). Also, Hot Hardware has posted a preview of the Leadtek Winfast S320 II after a hands-on look at a pre-production version of this upcoming TNT2-based accelerator. The board in the Hot Hardware article has a 150 MHz. core speed and a 170 MHz. Memory Speed, but the clock speeds for the TNT2 are not hard and fast, as this quote from the CGO article explains:

The actual speed of the cards will vary widely, depending on what the hardware manufacturers want to make. The least expensive TNT 2 cards will probably have the core processor at a clock rate of 125MHz and the memory clocked higher. This will deliver a fill rate of 250 megatexels per second, quite a bit more than the 180 delivered by current TNT cards. NVIDIA is recommending that high-end TNT 2 cards be clocked at 150MHz with a 183MHz memory speed, but there are already plans by hardware manufacturers to go higher. At least one brand of TNT 2 card will be sold at with a 175MHz core and 200MHz memory clock speed. This translates into an impressive 350 megatexles fill rate—nearly twice the current TNT. Some users may remember that NVIDIA's claims for the speed of the original TNT couldn't be met. The company is being more conservative this time around, and already have parts in-house running faster than the 175/200 speed that some high-end cards may use.