Shown at the Mobius Conference in Amsterdam, the next version of Windows Mobile will be "an update rather than an upgrade." This means that it's not Windows Mobile 7/Photon, which would be a huge leap in functionality, but more along the lines of the transition of WM5 to WM6.
Most of the stuff The Unwired saw behind closed doors is hush-hush so they can't describe it, but the new revision will be available starting Q1 2008, and will be on shelves in new phone form around Q2 or Q3. The good news for current WM users is that you can technically upgrade your old phones to the new OS, but it's up to the phone manufacturer—like it was for the transition between Windows Mobile 5 to 6—to determine whether they want to put the resources into doing so. [The Unwired]