I had an idea of water filling up the screen between the game space and the UI elements. I don't think the transition is there yet, but I think once the elements are in place the idea comes across. (The background here is actually a painting created by Tom Scholes, currently at ArenaNet).
Running this .swf in Scaleform solves the dithering problem seen while running this with a browser-based Flash Player.
Still, it needs something...maybe it needs bubbles. Yeah, everyone likes bubbles.