Let's dip our toes into the SpringSource Application Platform's Beta program. "Legacy" archives, i.e., WARs and EARs, are advertized as being supported, so theoretically one should be able to deploy apps even though they're not OSGi bundles. The Beta program, live since yesterday, seems a good place to start.
Not only am I hoping that there's nothing about Wicket that should prevent it from being deployed to the SpringSource Application Platform, but I'm also hoping that there'll be better diagnostics in messages such as the above by the time the official release comes out.
Nevertheless, aside from those caveats, I'm very impressed by the SpringSource Application Platform's ease of use and speed, even without OSGi bundle deployment. Have you tried it? Want to share your experiences here?