The New Times has put up a fantastic graphic on their Politics page showing a graphical breakdown on all 435 houses races.
You can select the races by which ones switched, which ones went for Kerry or Bush in 2004 and how they did in 2006. Margins then and now are shown for 04 and 06.
more below
Here is the link for everyone to puruse on their own.
http://www.nytimes.com/...
You can also review the district by income, race and a few others measures. There are metrics on which districts became more Democratic, etc.
Truly and fascinating graphic for junkies like ourselves.
If I find time later, I'll try and do a more comprehensive diary that follows the details, but for now I highly recommend this graphic.