The revolt appears to be spreading, according to TPM:
A vast majority of elected Republicans have signed Grover Norquist’s pledge not to raise taxes, and GOP leaders have strictly hewed toward it for years.There are now seven lawmakers (current and former) who have rejected Norquist's Americans for Tax Reform pledge. They are: the aforementioned Sen. Saxby Chambliss (R-GA), Sen. Tom Coburn (R-OK), Sen. Lindsey Graham (R-SC), Rep. Perter King (R-NY), Sen. John McCain (R-AZ), Senator-elect Rep. Jeff Flake (R-AZ), and former Sen. Alan Simpson (R-WY) who was a member of the Cat Food Commission.
But things have changed: anti-tax purity went out of style this election year, and the nearing “fiscal cliff” is motivating some influential conservative Republicans to speak out against Norquist’s pledge, wherein lawmakers promise to vote against any legislation that would raise new tax revenues.
Plenty of speculation as to what is really going on here. Are members of the GOP finally seeing the light on raising taxes on the idle rich? Or is this some sort of theater, the purpose of which remains unclear at the moment? None of the seven mentioned above, except maybe for Alan Simpson (and that's a big "maybe"), can be trusted as far as you could throw a small moon. Just a few months ago all were talking about eliminating whole government agencies in order to give their rich benefactors even bigger tax cuts.
Some have even speculated that Norquist himself is behind this little revolt. And it's a good theory. Norquist's style of bully politics works best when you can operate in the shadows. Constant media attention is the last thing he wants. So, why not construct a little show to make it appear that you have lost your influence? Then, once the media attention goes away, you go right beck to quietly twisting arms behind the scenes.
Am I giving Norquist too much credit? I wouldn't bet on it. He has managed to lead the GOP by the nose for more than two decades now. If anything, the guy knows exactly what to do to keep his congressional peons in line.