Progressives will rage, but I suspect a deal that looked something like this would have us all coming to terms with the political genius of the maneuver years down the road:
1. Raise Medicare to 67 in exchange for a raise in top rates
2. As part of the deal, a truce called on Obamacare
3. Subsidies available for 65, 66 year olds via exchanges; also, potentially, Medicaid
There's no question raising the age to 67 is a symbolic move in terms of "fiscal responsibility", but symbolism carries great weight with Republicans. Progressives will hate it, like they hated the Obama capitulation on taxes 2 years ago, but of course now we're realzing what a brilliant move that was all along.
Getting Repubs to capitulate on rates will effectively shatter the one ironclad plank holding the conservative coalition together. It is absolutely essential to breaking the Republican fever. A present vote on the Senate middle class tax bill won't be good enough; we need a substantial number of Republicans on record with a yes vote for a package to effectively include tax hikes on high earners. We already see cracks forming in the GOP coalition. This would be the fatality. Thenceforth, the GOP might be a party that can govern once again. (Their House majority will stand, probably for several election cycles to come, but I'm more interested in bringing the current GOP leadership to a position of reason and good governance than I am with undoing their majority, at least for now.)
Again, Progressives will hate it, hate it, hate it .... until the fine print sinks in. As part of a deal, the Speaker could be made to come to a gentleman's agreement, even an unspoken one, to call truce with the President on Obamacare. Furthermore, I'm sure the President will be very much mindful of the difficulties faced by seniors looking forward to Medicare and will take full advantage of the Obamacare framework to cushion the blow, perhaps to the extent that there would effectively be little difference. Boehner is probably also well aware that raising the eligibility age is more symbolic than anything and would agree to provisions softening the blow, if needed, as a part of such a deal.
So, if a deal does emerge in which the Medicare age is raised, take a deep breath and trust your inner Obama; he's got this.