The northeast will shed congressional seat while the South and Southwest pick up seats in 2011, based on the U.S. Census data recorded this year. The political implications are interesting. While the south is a stronger Republican region, it is likely that a good portion of that population growth is due to immigration (hispanics). The hispanic vote trends Democrat, although by no means a lock.
More generally, I am under the impression that regional differences are the single most overlooked and important factor in U.S. politics.