FWIW, I do not expect a realignment with Obama as a candidate.
I can see one happening soon, however, depending on how the left/progressives and right/conservatives shift in defining themselves in the next 2 elections. Think left-populism vs. tech-savvy-independent for Democrats, and socon vs. libertarian for Republicans. If the Dems went more populist and the Republicans more libertarian, with Dems adopting more socially conservative views and Republicans a more tolerant tech-savvy posture, you could start to see a significant realignment which actually strikes me as a bit more intuitive to existing and especially future demographics (think a Mountain West libertarian vs. a Rust Belt populist).
Just for for sh**s and giggles, imagine this electoral math:
Pro-business libertarian vs. populist social conservatives. (I've assumed a balanced electoral map due to the necessity of electoral sensibility and the establishment of a new middle.)
I know, long-shot, but I personally feel states like MN and TX are a lot more similar in attitude than the current political cleavages show. Austin is similar to Minneapolis, and podunk TX is similar to podunk MN. TX is certainly more socially conservative overall but TX is also less authoritarian.
I'd see the battleground states being CA, FL, PA, and possibly the pro-business south (GA, TN, NC, TX).
Anyway, probably rolling off topic at this point.