But as per my knowledge DAY software groups does provide some connector for Interwoven Teamsite.http://www.day.com/site/en/index/solutions/content-centric_infrastructure/Content_Repository_Connectors.htmlPlease have a look.
i remember at one point the architecture for one of the clients i worked for was entertaining the idea of using JSR 170 as the repository that didnt work for number of reasons . i am curious if u did this implementation to share ur experience with us