Micheal wrote an excellent overview of the new features in 1.1.5:
Michael, by the way, is the guy who has been responsible for making sure
that Seam runs on as many platforms as possible. (When we say that
supports a platform, we mean we actually tested it on that
platform, and we actually ship with an example application that
deploys on the platform.)
There's also a discussion going on at TSS. Please feel welcome to ask questions there...