Condi is very, very special. If the Republican Party doesn't find a spot for her on it's next presidential ticket, it would be unforgiveable (unles she genuinely doesn't want to run for elective office).
Frankly, I don't think there's anyone other than Condi who could effectively carry-forward the "Bush Doctrine" in 2008 and beyond. Personally, I have to believe that by the end of 2006, a clear frontrunner for the GOP nomination will emerge, and they'll probably have Karl Rove's fingerprints all over them.