I think it is a little early to do a universal 301 redirect of all of those sites to your main site. Some of my sites affected last month have already started to come back. I would try to continue to get them to come back a bit.
You could get some more topical content on them and maybe clean them up a bit.
Then wait.
If that still does not work and you don't want to maintain or track them you could do 301 redirects. I dont think you will pass any penalties. I have done this myself and did not see any ill effect.
It seems that when penalties happen they tend to be to a directory or a domain. The penalty does not seem to get passed along.
Anyone else seen any bad things happen when a 301 redirect was done?