Microsoft has released Windows Mobile 6:

BARCELONA, Spain  Feb. 12, 2007  Microsoft Corp. today unveiled Windows Mobile® 6, the newest version of its mobile software platform. By improving usability and adding support for Microsoft® Office features previously available only on PCs, Microsoft Windows Mobile 6 delivers to the small screen a familiar and rich experience that meets the needs of work and life while on the go, all with a single device.

Smart phones running Windows Mobile 6 are expected late this year. Currently, Smart Phones running Windows Mobile work with the OncellRx medication reminder service. Smart phones with Windows Mobile 5 include: