SC,
It might be struck down by the Supreme Court, but not necessarily. That's a lot harder than people seem to think, even for genuine missteps. First of all, the Supreme Court has a tradition of not getting involved in fights between Congress and the President for any but the most extreme cases. Second, you'd have to find somebody with standing to bring this case, and it's not completely clear who that would be (Congress is probably as good a guess as anybody, but see above). Third, and related once again to one, a Supreme Court giving a President an edict about how to do his job would be almost as troubling as the President not doing his job (which is part of why they'd be extremely hesitant to take the case).
So, that might be tried, but it's not clear it will work even if the President is wrong. And again, it's not clear they'd win: as I said before, I think this is very important ground for Congress to stake out, but it's a gray area legally. The issue is, you can't have Congress ceding all the gray areas or you have a terrifically powerful President, and one who is almost certainly violating the Constitution. (Think about Bush and some of the foreign policy stuff. He had colorable legal arguments for almost everything he did, but that doesn't mean it was a great idea for Congress to lie down and let it happen).
So, no, I was referring more to political consequences of the traditional kind: power-of-the-purse punishments, nominations, etc.
@Jeff,
It's possible to be on the right and wrong side of history at once. I tend to agree with most aspects of the *policy* of what Obama did; but this was *no* way to do it. Process is important. Congress absolutely should, eventually, enact a law containing this, but it became much more complicated to do it. Obama was on the wrong side of history in his huge power grab, and I only hope it goes down as an isolated incident (much like Andrew Jackson's flouting of the Supreme Court, which of course in fairness was more black and white wrong).