Does this mean that the NV28 is just a replacement for the GF4 4200, not the GF4 4600?
http://www.tomshardware.com/mobile/02q3/020829/radeon9000-13.html
NVIDIA will try its best to catch up soon. It won't take long for NV18M's release, something like GeForce4 Go460 with AGP 8x support. Only a short while later, and probably before the end of this year, there will be NV28M, a mobile derivative of GeForce4 Ti 4200, which will probably beat Mobility Radeon 9000 in 3D performance, but lag behind it in terms of power consumption. What NVIDIA is really waiting for is the NV3x family of chips. In the Spring of next year we will see a notebook chip in 0.13 micron process with DirectX 9 support. Until then, NVIDIA will have a hard time to compete with ATi in the notebook arena.
http://www.tomshardware.com/mobile/02q3/020829/radeon9000-13.html