I don't think a Conservative revolt can succeed. It could be worth a try, but I think there is a great danger that it could splinter the Republican Party and usher in a Leftist Radical (i.e. Democrat = Communist) takeover of the United States.
Remember the Radicals of the '60s--the Weather Underground etc.?
I think our wisest option is to support McCain, do everything we can to choose a conservative Vice President for him (he could be a one-term President), and work like crazy to elect as many Republicans as possible to Congress.
We should also do everything possible to discourage support of Bob Barr or any other third party candidate who might drain votes from the Republicans.
If the Radical Leftists (Democrats) take over the government in sufficient numbers, the U.S.A. will not recover.
In 1964, Conservatives secured the nomination of Barry Goldwater from the liberal establishment - he lost, of course, but helped launch the political career of Ronald Reagan, who became governor of California in 1966. Moderates reasserted themselves in 1968, with the nomination of Richard Nixon.
In 1976, Conservatives put on a show at the RNC, where a sea of cowboy hats cheered on Ronald Reagan in thrilling act of insurgency against President Ford, who won the nomination but lost to Jimmy Carter. Reagan, of course went on to trounce Carter and re-establish conservative ascendancy within the Republican Party.
By 1988, the moderates were back, with George H.W. Bush doing his "kindler, gentler" thing. After Gentle George was shellacked by Billy Bob Clinton, conservatives decided to make a Congressional stand and in 1994, led by Newt Gingrich, moved into control of Congress for the first time in two generations.
14 years later, that's all gone. We have a weak conservative President and a Democrat Congress and a public in a sour mood. We have an older, moderate "maverick" Republican as presumptive nominee against a young, doctrinaire left-wing Democrat. I don't see that as a very promising match-up for the older guy, hence my interest in another little cowboy party at the RNC.