The current idea is a "repeal and delay," killing the subsidies in three years or so, creating a ticking time bomb under which a full replacement must be done or the healthcare system collapses. Yeah, nothing could go wrong there... I did a series back in August called "Political Science and Craziness" on the use of threats to cause mass destruction, and how you need to appear wacko to pull it off, and perhaps we'll revisit that soon, along with good, ole' Thomas Schelling, but for now, let's talk about why this is still such a mess with some taxonomy! Yes, taxonomy! Here's a basic categorization of your Obamacare opponents.
1) Those who oppose the principle of economic redistribution. Stripped of everything else, Obamacare is Robin Hood-ism. It taxes rich people to give healthcare to poor people. Sound good to you? Then you will at least like the concept of Obamacare. If not, then you won't even agree to the concept of Obamacare. This is a big chunk of the Republican Party. This is where a big problem comes for the "replace" part of "repeal and replace." You can't replace a law you don't want to replace because you oppose the whole underlying concept. This is about the fundamental disagreement between the parties on redistribution.
2) Those who oppose anything attached to Obama. Yes, that's a big part of it. Presidents turn everything partisan. Key scholar here: Frances Lee. Just by being associated with the structure of the law, Obama makes Republicans hate a policy that, at its core, is basically what a Republican Governor passed in a New England state because the Heritage Foundation proposed it as a counter to the Clinton proposal in the early '90s. The problem with these people? They aren't really thinking about policy, so it is hard for them to support a replacement.
3) Morons who don't know what's in the law. Death panels! Government takeover! Does anybody remember this idiotic nonsense? This is the kind of shit we saw at tea party rallies and town halls when Congress was debating the bill, and the Republicans in Congress who still think this way (John Boehner called them the "knuckleheads") just can't be reached for any kind of replacement because, well, they're what former Republican Speaker John Boehner called them. Knuckleheads. Is it any wonder why Boehner cried, chain-smoked and drank a lot? Poor guy. I liked him.
So, among these three groups, where are your replacement constituents? Your best bet is among group 2, but even then, you have to be careful to make the structure as different as possible from Obamacare. You can try among group 1, but only if the bill is as stingy as possible, defeating the purpose of a replacement. Group 3? Um, here. Have a shiny object to play with. Now, try not to swallow it. Or, better yet. Try to swallow it. Please. For John Boehner's sake.
Anyway, will Congress actually go through with this? I still don't know. I just revert to uncertainty these days, but there's your taxonomy. Remember, the Republican Party is largely opposed to economic redistribution. That's kind of its raison d'etre.