I could see if the DEMs win in 08 the republicans fall apart with many libertarians and Paleo-cons joining the LP and CP and before 2012 I could see Schwarzenagger, Bloomberg, and Lieberman getting together and forming a new Centrist Party.
I don't know about that. I definitely think that in western cities(San Fran, Seattle, Denver, Boulder, Las Vegas,) and in New England, you know, the bluest parts of the country, might see the defunct Republicans being replaced by the libertarian party and the populist to paleo-conservative Constitution Party. On the other hand, if the DEMs lose, they may be replaced in swing and conservative states by the Libertarian Party for the bedroom democrats and the Green Party for enviromentalists and unions.