I reserve judgement on the R600 until at least some reviews are released. IMHO though I can't see the R600 beating the 8800 by much, I can see it playing out a lot like the 7800-1800 thing. 1800 comes out faster than 7800, super extreme edition is released to keep performance lead and then die shrink 7900 comes out with better performance. The die shrink R600 (or 650 or whatever it's called) could fit into this model like the 1900 did. Taking the lead by a small margin.
Just my 2 cents.