Vodkapundit notes that every Republican in the House will vote to repeal Obamacare or face a primary challenge from the Tea Party. He is almost certainly right. That translates, in this Congress, into a minimum of 242 votes, a sufficient number to pass the repealer, but not enough to override the expected veto.
The nit I wish to pick is his next comment: That the magic number to override the veto is 290. True enough, in the House. But that is the wrong battle to watch. There will never be a veto if repeal doesn't get through the Senate, where reside a mere 47 Republicans, whose number includes the Ladies from Maine and several others of a less that completely conservative bent. Should repeal somehow pass in the Senate, Obama's veto is far more likely to be upheld there than in the House (referring again to the Ladies of Maine, among others).
I don't know how likely the House is to muster 290 votes for repeal. It does not seem impossible to me. But Mitch McConnell would qualify as the greatest magician of all time if he managed to pull 67 repeal votes out of his hat.