I personally think that the insurance companies are going to crack down on the HP wars in the very near future. They are going to refuse to insure certain cars, or make them unattainable to most people in an effort to keep them from selling.
While we are on the up and coming bandwagon, it looks like there is a 650 HP McLaren inspired Viper on the horizon, perhaps as a “Special Edition” for 2007 (existing body) then added to the lineup in 2008 as an “ACR” type version with the new bumpers/hood to meet new regs.