that much more? damn, 90nm is lower clocked but produces better performance at stock speeds VS 130nm. Consumes less power and generates less heat, theoritically better OC stability and headroom. $100 more? shop somewhere else, shouldn't be that much, or maybe its cause of the demand, newegg seems to jack up prices for high demand parts. A month after 90nm release, I was seeing prices about the same range at 130nm, so definitely hold out till prices water down.
90nm all the way, although you might have to do some bios flashing on mobos out before the 90nm were.