I have seen some nice ranking boost by getting .edu and .gov links. I would say more so than if they where .com's.
if its the same pr and the link the same dofollow and in content then it would be better on a .edu or .gov site for sure
.edu site have more traffic that why if you post your link in these site then your site traffic also increase
I have 4 sites, 1 I used .edu recently that was on page 2 of google and after 7 months of paying SEOs I tried something and created an .edu blog and put the link in there now the website is sat on page 1 of google in position 5. So it DOES work!
I do a bit of launch jacking and building links for customers launch jacking projects. I always start off the process by building a good amount of .edu and .gov links. I then fire a huge volume of links in to those links and my money site and I have seen some pretty special things in ways of rankings and PR.
Several sites get better pageranks and become stronger when have .edu backlinks. I'm questioning myself too: where can I get this type of backlinks?
Here's a nice article from SEOMOZ that was just released yesterday. While it doesn't specially speak about .gov or .edu, it does have a mention on how to value the links. http://www.seomoz.org/blog/understanding-link-based-spam-analysis-techniques