Maps and Data of the 2010 Redistricting Cycle
More information is available in the writeup for each state -- just click on the state's name.
Daily Kos has some statistics, particularly the redistribution of constituents among congressional districts.
The Brennan Center has a Google map of new districts with a political forecast based on past elections.
Michael McDonald also has links for some states, disaggregating recent election results to census blocks
(these block results can be reaggregated using the block files below to compile "results" for the new districts).