If Obama has a filibuster proof Senate and a sizable House majority, he most certainly could do a lot.
I do agree that he can't do much on many of the hot button issues. The hard reality is that a premature retreat from Iraq will be the dumbest decision ever and his minders will make him see the light. Social Security, Medicare - he will raise taxes on the evil rich but that merely delays the Ponzi collapse and passes the problem along to the next administration(s). Energy - he won't improve the supply of energy by even one BTU. Stock up on warm sweaters for the winter. An oil company "windfall" tax? That's just the kind of incentive that will have the oil companies rushing to invest (sarcasm). Middle East - he has no choice but to kiss the same butts that President Bush has been locking on to. Food prices - will he scrap the ethanol boondoggle? Nope. Health care - HillaryCare got crushed and ObamaCare will do no better. Education - zilch.
So what can he do? Higher taxes, not to raise revenue but to punish the evil achievers and make it "fair". Lots of talk with dictators.
Now that's change that we believe, like, and stuff.