While the code has yet to be written for many of the items, the design of Wayland is allowing for a number of features not supported or cleanly possible with X. Back in November I mentioned two of the features, which was GPU switching and better full-screen support. Since then it's also gained support for a nested compositor and in February I mentioned the multi-monitor plans for Wayland that are superior to what an X.Org Server can offer. There's also been talk of it on the network and various other features.
In related accomplishments in recent months, there's now the Wayland back-end to Clutter and greater GTK+ support for Wayland. GNOME, KDE, or any other desktop environment cannot yet run natively on Wayland (without just running a nested X Server within there for compatibility), but progress in this direction is being made.
The latest feature of Wayland to be talked about where Kristian Høgsberg, the founder of the Wayland Display Server project, has commented is in regards to Wayland's screensaver capabilities. Right now with screensavers under X it's basically capturing the input and continually redrawing over the display.
With Wayland, Kristian plans for the lock-screen to be part of the Wayland compositor. In having the compositor handle the screensaver role, it can ensure that no window can appear atop the screensaver surface, it can properly detect idling and grabs already, and has complete control over the screen. Unlike the X design, there wouldn't even need to be a screensaver "window" that's on top but the compositor could just keep painting a black screen. For those interested in a "fancy screensaver", a plug-in could be used or an out-of-process Wayland client for drawing whatever you desire.
He made these comments on the Wayland mailing list.
In terms of Ubuntu's adoption of Wayland, the last I talked to Mark about it was back in March at which point he believed Wayland would only be used in special cases for Ubuntu 11.10 or 12.04 LTS.
My belief is they won't pick it up seriously until at least Ubuntu 12.10 when it should be in better shape, past the next Long-Term Support release, and the Wayland clients are ready. By Ubuntu 11.10 though (this October) we will hopefully see the upstream components playing with Wayland in some form that this next-generation display server can be at least experimented with by enthusiasts.