khanmeister said:
My guess is ATI will own the 6800 probably before it is easy to get ahold of.
With so many unconfirmed rumors floating about from both camps, I am not quite sure who's gonna up who. What is for certain is that Nvidia with it's 6800u has just raised the bar by a fairly large margin. Both in terms of performance and features. Here is a list of features known on the Nv40 so far(we won't know all until we have these cards in our own hands):
New 4xRGMS FSAA(more modes might be added with driver updates as in the past with Nvidia)
The hybrid mixed mode Super Sampling mode FSAA are still available as well as old OGMS FSAA modes(why?). Super Sampling FSAA + AF is an interesting mix(seems to apply higher AF on textures)

.
Options to choose Full Trilinear Filtering(actually works now) or older Brilinear filtering
Now has the same angle dependent AF as ATi(less performance hit)
Could also have an option for Nvidia's old Angle independent AF through drivers(larger perf hit)
Shader Model 3 compliancy(how much this will affect future games still remains to be seen) - Far Cry should have it soon though so we can see..
Mpeg/Divx decode/encode in hardware
From the current rumors floating about, it seems that the R420 may be a little faster than the Nv40, but will probably have less features and options. But until all these are confirmed, it's hard to be conclusive.
There's even rumors from some well informed people that the clock speeds on the Nv40's aren't final yet or that Nvidia is waiting for ATi to release information about the R420, then released Higher clocked Nv40's. Like I said, too many unconfirmed rumors at the moment.
Also, it's likely the X800pro with 12 pipes will be competing with the 16 pipe 6800u for a few weeks or a month until Ati Releases it's X800Xt with 16 pipes as well. Who knows, maybe by then Nvidia will be releasing it's higher clocked models to compete with it.