We jst got back from presenting a very large deal to a customer for Hosted Exchange, Office communications server and Sharepoint.  This client would be migrating from a very large Novell Groupwise environment.

I was able to locate some very useful information about Novell Groupwise to Hosted Microsoft Exchange here:

In addition to that the Quest Software Groupwise to Miocrosoft Exchange Migrator is always a useful tool for these migrations.