RIM now officially supports GroupWise 2012 with BES 5.0.1. Here is the Blackberry Enterprise Server Compatibility Matrix.
BES support for GroupWise 2012
About the Author: Marvin Huffaker
Marvin Huffaker is one the most experienced Micro Focus GroupWise experts in the world, providing independent consulting services to business customers globally. When it comes to GroupWise, there aren't many people that have made a career supporting it almost exclusively. Marvin has been working with GroupWise for over 15 years, has been through extensive training, has lectured about GroupWise migration strategies, and has been heavily involved with the GroupWise Beta Team for many of the recent GroupWise releases. When you work with Marvin Huffaker, you're working with one of the best in the industry!