In other words, he's still keeping his options open. And he voted against the Ryan budget resolution, likely because he wanted to keep clear of taking a stand on Medicare in advance of his race for Senate next year against Sen. Jon Tester (D).
So far though, he's keeping his options open. But we should expect he'll get pressed hard to take a stand one way or another as part of what's sure to be a extremely hard fought election next year.
In a different category is Rep. Dean Heller (R-NV). He's running next year for the seat vacated by Sen. John Ensign, running against Rep. Shelley Berkley (D). He voted for the Ryan resolution and has openly embraced the part that phases out Medicare. So he's committed, on the record.
Watching these two races and other similarly situated ones will be a key tell to seeing how this question plays out in 2012.
Drop me a line if you see other races where candidates have taken clear stands one way or another or are keeping mum.