"...The only worry I could see is that it will receive less attention now it is under Oracle and they have a competing Java EE server..."
I got this comment recently on my blog
During JavaOne Oracle committed officially to Glassfish. WebLogic will also share some core components with Glassfish (HK2, probably EclipseLink, CDI etc.). See also official slides.
NEW: Online Workhop Effective WebApps without Frameworks is also coming to: MUC Airport.