Here I was hoping that this would be a thread about State Houses, not Governor's Mansions. South Carolina's not in any danger of a switch in 2006, bur elsewhere...
The Colorado Senate is a possible flip as the Democrats have only a narrow 18-17 majority and there are six term limited Senators, so a lot will depend upon whose terms are up.
The Indiana House is a potential flip with a narrow 52-48 Republican margin.
Iowa is definitely in flux with both the R51-49 House and 25-25 Senate susceptible to change.
Maine's House is at D74-73-4 up for grabs. and it wouldn't be impossible for the Republicans to gain the D19-16 Senate.
The Dems might gain the Michigan R58-52 House and the Minnesota R68-66 House.
Montana is in total flux with a 50-50 House and a D26-24 Senate.
If the Nevada Senate is up for election in 2006 its possible the R12-9 Senate could flip, but I wouldn't think it likely.
The same is true of the Washington D26-23 Senate, a possible but unlikely flip.
Oregon's R33-27 House might be vulnerable, but probably only if the problems of the national GOP manage to glom onto the local level as well.
There don't appear to be any other State Houses where a polarity change is likely.
In short I see 2006 at the State Legislature level being much the same as now.
I can actually see it happening that both houses in Minnesota flip (although unlikely). Right now the GOP has a 68-66 advantage in the House, while the DFL have a 35-31-1 advantage in the Senate, with the 1 supporting the DFL. I'd bet on the status quo maintaining in both though.