Bloomberg's BUSINESSWEEK did a real nice writeup on DeMint. He seems pretty grounded in his beliefs and I'd really be surprised if he capitulated.
I would think the best way to get rid of ObamaCare(less) is two-fold. First, don't fund it so it has to be break even. Then, make the opt out something like $100 or so.
Because unlike 99.9% of the 535 in Washington DC, DeMint was a businessman before he was a senator.