Kevin Holman's OpsMgr Blog : Native Exchange 2007 MP 6.0.6741.0 ships for OpsMgr 2007 SP1 users
If for some reason you cannot or will not upgrade to OpsMgr 2007 R2, then this update is for you!
This Native MP replaces the old “converted” Exchange 2007 MP. If you are running the old conversion MP then I STRONGLY suggest making the effort to transition to this MP.
Kevin Holman's OpsMgr Blog : Native Exchange 2007 MP 6.0.6741.0 ships for OpsMgr 2007 SP1 users