Nobody knows if R670 will be delayed ore not (yet), and certainly not Fudzilla Although my guess is we will see one or other refresh for autumn-winter. 2900 shrinked to 65nm and at higher clock-speed shouldnt be much brainer for AMD IMO. They already went through bumps migrating 2400-2600, add another half a year and its more than enough time for it.
Waiting for R700 in Q2+ 2008 and doing nothing till then would be pretty stupid, so we will definately see 670/whatever sonner than later. Just common sense.