My prediction: 5-4 to overturn the individual mandate as unconstitutional, on the grounds that upholding it would mean that there is no limiting principle constraining the federal government's power under the Commerce Clause; but 6-3 upholding the rest of the abomination (Obamanation?) as constitutional, even though the whole house of cards makes no sense and is unworkable without the mandate as a funding mechanism. The Court will say something to the effect that the economic impossibility of a piece of legislation is a question for Congress to fix, not the Court. Roberts and Kennedy will vote with the majority on both, Roberts will write the opinion for the Court; Ginzberg will write the dissent/partial concurrence.
The most likely alternative: a 6-3 decision upholding the whole thing as Constitutional under the Commerce Clause. I call this one the "That Boat Sailed A Long Time Ago" doctrine, which concedes that Leviathan exists and is all-powerful.
The second most likely alternative: a spasm of courage from Justices Kennedy and Roberts, who correctly conclude that the mandate is unconstitutional and non-severable from the statute as a whole, since it is patently the linchpin of the entire scheme.
9:00 am central tomorrow. Check the SCOTUSblog for live-blogging of the decisions.