Exchange Team has released the first update rollup for Exchange 2010 server which solves a number of issues. More info about the problems it solves is listed here
As usual, Exchange 2010 must be installed and any interim updates should be deleted before this rollup is applied. Interim updates are only given out to customers (if needed) by Microsoft Support to resolve an open case.
Download the update rollup here
Exchange 2010 now supports Blackberry Enterprise Server 5.0 Maintainence Release 1 (MR1) with this update rollup 1. More info @ ExchangeTeamBlog