I disagree with some points above.
.edu comments on blogs will help, but indeed they can be removed.
5 - 10 quality edu links can make a tremendious difference. It depends on your KW.
That said, i've read somewhere that google intend to review the value of an edu link, which stilll has to be confirmed as there were no public release from it.
The key remains link diversity. Shitty links, quality links, web 2.0, social bookmarking, wiki links, articles links, forum links, contextual and so on.
What is working great these days are blogs network.
GL