I've had a very quick look at it and done some screen shots. I need to play around with it in much more detail and do a full write up about it soon.
Also released recently was the Windows SideShow for Windows Mobile Developer Preview v0.01 enabling Windows SideShow Gadgets to run on the windows mobile platform, so the two together are definately worth looking at. Using your Windows mobile phone or PDA to control your Media Center system sounds pretty cool to me and it's what we have been waiting for!
Now Playing Controls
I've opened a new thread on TGB here to discuss this new SideShow Gadget.
If your having problems downloading this from Microsoft connect:
"Clicking on "click here to download" = Page Not Found The content that you requested cannot be found or you do not have permission to view it."
You need to look for the Windows Sideshow Connection at Microsoft Connect.
Media Center Gadgets - General Information and Known Issues There are 4 Media Center gadgets: Download and install the Beta Media Center Gadgets: Click here to download
Browse TV and schedule recordings. Browse the TV program guide, view metadata on upcoming or current shows, and pick shows to watch and record (single showing or series), without interrupting the TV viewing experience. Recorded TV. Select a previously recorded program to play back, without interrupting the viewing experience on the TV.
Play Music. Browse the media library, control music playback on the PC by using the remote control device instead of the primary display, such as a TV. Play radio presets. Browse your radio presets and playback that station through your Media Center.
Pictures + Videos:
Browse the picture and video libraries. Make a selection on the remote and that picture or video will be displayed on the TV.
Provide "now playing" information. The remote control device shows information about the currently playing medium, such as the track title or the time elapsed. Known Issues: Enabling the Gadgets on more than one SideShow device to control the Media Center PC is not supported for Beta Enabling the Gadgets for more than one user session on your PC is not supported for Beta