So far, and this is just tentative, and just my opinion, I don't think that Obama represents any sort of significant positive change. That is, assuming Romney gets the GOP nomination, then I don't think it matters who gets elected to the presidency.
For example, Obama recently temporarily stopped the TransCanada oil pipeline to Texas. A good thing imo, because I think that what's needed is more American refineries, not a pipeline to Texas for eventual export so that the oil companies can maximize their profits.
But it remains to be seen what the eventual outcome will be. I'm betting that, eventually, Obama will go along with it (and of course Romney is pro-pipeline all the way), and then we'll see the usual discussions about how he was forced to do it because of unreasonable Republican intransigence or whatever.
I also don't think that Obama is going to spearhead the enactment of sufficient regulatory measures wrt, say, the financial industry. Or that he's going to lead the way to significant changes in the tax code ... etc. In short, flip a coin, it will be business as usual either way.