The first GeForce 4 articles are hitting the net, though NVidia still hasn't officially announced the chipset (ok they have now). Right now there are articles at Tech-Report and HardOCP (which includes benchmarks) though suffice to say there will be more this morning.
So is NVidia's latest a winner? Sure its faster but again there are no games using its features much like with the GeForce 3. However it looks like you can crank up that anti aliasing since that got a whole lot faster. To check a benchmark from Kyle, where a GeForce 3 Ti-500 scored 31fps in a 1600x1200 Quake 3 demo with 2xAA, the GeForce 4 Ti-4600 gets 72fps. Not bad at all.

GeForce4 Ti cards will come in several flavors. The GF4 Ti 4600 will feature 128MB of memory and the aforementioned 300/325MHz core/memory clock speed. At these speeds, the Ti 4600 cards will be unquestionably faster, in terms of fill rate, than ATI's top-end Radeon 8500.
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Here are the things NVIDIA is going to want you to pay attention to:
- Most powerful GPU in the universe – 10.4GB & 136M vertices per second of graphics processing power.
- Accuview AA – Delivers unbeatable visual quality and frame rates.
- nfiniteFX II – Engine drives complex geometry and animation.
- nView – Display technology provides the ultimate multiple display flexibility and user control.

I'll keep this story updated with more articles as they come in.
Update: More at AnandTech (with Unreal Performance Test 2002 benchmarks), NV News, GameSpy, Hot Hardware, 3D Blaster 4 MX420 review, Guru 3D.

Update 2 Here is the official PR on the GeForce 4. The MX boards will be out in the next two weeks, Ti boards in about a month.