Here are a few media articles on the subject. Hard to know how much is hype - there seem to be only a few articles from credible publications out there - but I find it interesting that some athletes/teams are getting on board. Some of the quotes suggest that DHA is the substance that researchers are most interested in (ie, as opposed to EPA). It's unclear what the optimal EPA : DHA ratio in fish oil is for people recovering from a concussion.

http://sports.espn.go.com/nfl/news/story?id=5995704

http://www.nfl.com/news/story/09000d...n-issue-headon

http://randybirdnutrition.com/2010/0...otball-helmet/

http://www.post-gazette.com/pg/11002/1115033-139.stm