Over at RCP, Sean Trende points to some recent polling data suggesting that Republicans are liable to pick up a substantial number of governors' seats in November, leaving Democrats with their smallest percentage of governors since Reconstruction. I'm not sure this will happen (Trende is also quite confident that the GOP will take over the House, which is far from certain. Also, as Trende notes, the latest polling doesn't account for some recent meltdowns like Scott McInnis' here in Colorado), but this strikes me as an important topic that doesn't get enough attention in election coverage.
What would it mean for the GOP to occupy three quarters of the governors' mansions? Well, as Trende points out, the big impact in the near term would be in the area of redistricting. In states where the legislature gets to draw up the new maps, those legislatures would suddenly need to accommodate the views of a Republican governor. That could mean an entirely different approach to redistricting: A Democratic-run legislature might seek an incumbent-protection approach, protecting everyone's districts, rather than trying to gain new seats for Democrats. A Republican-run legislature might do the opposite, claiming more House seats for their party.
It gets more complicated in other states where commissions determine the shape of the new legislative maps. The governor may have an impact on those commissions, but it's far less direct.
Has anyone seen projections for the number of state legislative seats Republicans are poised to pick up or lose? That would be an extremely useful statistic, although I don't know of any website dedicated to this.