This sounds like an important clue from Eric Cantor:

House Majority Leader Eric Cantor (R., Va.), speaking at a Friday press conference, said Republicans needed to "see some will" on the part of the Obama administration to meet GOP demands.
"I can tell you that everything is on the table, other than raising taxes on the people we need to help create jobs," Mr. Cantor said.

What's the clue, you say? Cantor didn't rule out raising taxes there. He just ruled out raising taxes "on the people we need to help create jobs" -- i.e., rich people. Aside from the further philosophical insight this provides into the Republican view (which is that the interest of the economy is synonymous with the interests of the rich), that does suggest a possible deal: Republicans would agree to higher revenue, but only on taxes that don't impact the rich. I suppose Obama could swallow this, on the assumption that he can win reelection and hold the line on extending the Bush tax cuts on income over $250,000.