Just couple of days back we previewed some upcoming changes in Ubuntu 11.10. All these changes have landed in Oneiric after recent updates.
New ALT+TAB switcher is now built into Unity itself and now does not need to depend on a compiz plug-in anymore. However, currently both the new switcher and application switcher compiz plugin are enabled but this will probably change in future updates.
New application switcher can be accessed using CTRL+TAB at the moment (screenshot above). Also there is a minor change in switcher as now a Show Desktop icon is always present by default to minimize all active windows (same as Super + D shortcut but it does not brings back minimized windows - bug?)
Initial work on dark toolbars for Ambiance has landed but they require more work to better integrate with the desktop.
Lastly, compiz grid plugin (window snap feature) has now better and smoother fade animations but a more lighter tone to grid indicator colors will be probably more cooler for the eyes.