New Zimbra Mobile Connector for Blackberry Enterprise Server release & updated docs as well: http://www.zimbra.com/products/bes_trial.html
It's very important to read the docs regarding this release.
We have shifted our requirements to go from Outlook 2003 to Outlook 2007. This is due to some Microsoft issues that were fixed in Outlook 2007 but were causing us stability problems when running ZCB against 2003. It is STRONGLY recommended that you upgrade your version of Outlook. This upgrade along with some changes that we have made, will really positively impact server stability and longevity.
We have also increased the max number of recommended users from 20-25 to 50.
Multinode ZCS configurations are supported and multi-agent BES enviornments are supported.
-The Zimbra Team