A common question we get is "hey, what happened to feature <x> that we saw demonstrated years ago?" The most common one of these lately has been the floppy windows that we showed off at WinHEC. After the XGL stuff started making the rounds on youtube this year, people have been asking why Vista doesn't have floppy windows now when clearly it was working in 2003. If you don't know what I am talking about, one reader provided the following links:
http://www.extremetech.com/article2/0,1697,1154262,00.asp
http://www.youtube.com/watch?v=pYHcAO2VxFQ&mode=related&search=
The answer is pretty simple. Floppy windows - while very cool - actually detract from the usability of the system for most people. It is one of those things like the genie effect in OSX: super cool when you first get your Mac, but then you turn it off after a month because it just becomes annoying. All the power to make floppy windows is still in the DWM, but we are using it for things that really improve the user experience: live thumbnails in the task bar, live thumbnails in ALT-TAB, the whole Flip 3D thing, and and the subtle visual effects for maximizing, minimizing, and restoring windows.
Don't get me wrong - we have only just begun to figure out how the amazing power of the DWM can transform window management. There will be huge innovations in this space as time goes on. But with a user base the size of Windows, we need to be careful and considerate with our UI changes, and not introduce a bunch of weird concepts that we don't feel really add anything.
Of course, nothing is stopping some enterprising DWM expert from creating a Power Toy to do some of these things... I'd bet that after Vista is out there, we will see all kinds of weird DWM hacks. I personally am looking forward to it!