Yes, we're supposed to find out today just what the Supreme Court of the US thinks about the ACA. So what do I expect? I expect four months a few days of the talking heads arguing that it was the right decision, or the Court is completely bogus and bent to political pressure, how whomever's decision or descent is a bunch of hogwash that doesn't stand up to the light of day, how we need to repeal the whole thing, how we need to replace the whole thing, how we need to tinker at the edges. I expect all that.
How they'll rule, well I'm just in the dark as you. If I had to make a guess, Scalia's recent ravings sounds like he was losing the argument and he was looking to make a pre-emptive "my vision is the correct one". But that's only a feeling.
When the news organizations polled Constitutional Scholars and lawyers, the majority said it'll be upheld in full. There's no Constitutional basis to strike it down. But the Supremes have never really been held to the Constitution, they are, after all, not Constitutional Scholars (although some fancy themselves to be). And that the majority of them are actual lawyers and have been judges in other courts is a historical anomaly. So, they could go either way or any of the thousand permutations in between.
Also, I expect the internet to slow way down at around 10 am Eastern.