It won't change anything. The issue was, and will remain, political (note: I'm assuming that the Supremes will strike down the mandate but rule that it is severable, i.e. the rest of the statute stands).
And so politics will continue around this. Actually, things will be more urgent, since without the huge amount of money from the (typically young and healthy) uninsured, the costs will explode. Also, the Insurance companies will find that their cunning plan to collude with Big Government to get 30 Million more customers forced into their plans will be facing bankruptcy, sooner rather than later. Asshats. Watch their stocks all tank (maybe 25% drop) in the minutes after the ruling is announced.
Now, I could very well be wrong here, and the SCOTUS could rule that Congress was free to include a severability clause (and in fact did so in a draft; the clause was removed before the final bill). But I don't get the feeling that there isn't a majority willing to play wise King Solomon.
And so to the politics. Mitt Romney has been rather loudly saying he'll repeal the bill. Of course, he can't (Congress is the only one who can repeal a law, unless you use the new Obama rules - which Romney won't). The Republicans need to win back the Senate, which is plausible. But they also need to win a filibuster-proof majority, which is vanishingly unlikely.
And so politics will be intense all through 2013 as the Democrats scramble to keep what's left of Obamacare via filibuster, and Republicans seek wobbly Democrats up for re-election in 2014 to peel off from the herd. The Main Stream Media will be going insane, and the Eurozone will be shedding member states, GDP, and jobs. I expect to see the half trillion "taken from Medicare" play a big role in that election.
That last will hit us pretty hard, and so the question is whose message will prevail: Democrats wailing that it's all Romney's fault, or Romney pointing out what a disaster the Democrat's "accomplishments" have become.
And so, today is not the end. It's not even the beginning of the end. With Romney and the GOP establishment, it's perhaps not even the end of the beginning.