Sony Ericcson has just announced their 1st Windows Mobile phone, it's called XPERIA. The specs are pretty impressive.
Windows Mobile 6 Professional
3-inch wide VGA (800 x 480) touchscreen display
full arc-sliding QWERTY keyboard
3.2 megapixel camera
A2DP Bluetooth
GPS
WiFi
quad-band GSM/EDGE, and 900/1700/1900/2100MHz UMTS/HSDPA/HSUPA (or 850/1700/1900/2100MHz)
microSD
400MB on board memory
New panel interface
The XPERIA will ship in the second half of 2008.