From Engadget: Microsoft wants to kill the BlackBerry dead with Windows Mobile 2005
One has to understand RIM's ace: they are already installed on thousands of enteriprse servers. Simply bringing out a new OS will not kill the Blackberry.
Here are the issues:
1. Is convergence of phone, PDA and wireless email ever going to happen in a manner that the market buys in mass quantities. (The RIM 7100 and Axim X50v make a great complementary combination.)
2. How far do RIM's patents for email extend to "wireless email" on PDA's? Note that all the major player such as Nokia, Palm, etc. have been licensing RIM's email patents.
It will be interesting to watch.
(From someone who has been watching RIM since 1997 and a shareholder since 1998.)