How will Play! framework + Vaadin work? I'm looking over the shoulder of a colleague that's developing a Vaadin app, and it seems the Vaadin Eclipse plugin generates its own web app structure (web.xml, etc.) with only the one dispatcher servlet. Also, the whole point of Vaadin is programming the presentation layer "GUI builder" style (e.g. like Swing), so there's no HTML templating, etc.
Is there any role for something like Play! in a Vaadin app?