After a long wait (definitely more than 90 days) the management packs for MSMQ 4 (Windows 2008) and MSMQ 5 (Windows 2008 R2) are finally released.
Both seem to be fully Cluster aware and pretty much holds the same monitoring as the the latest MSMQ 3 MP.
Message Queuing 4.0 Management Pack for Operations Manager 2007
> **Quick Details**
Version: 6.0.6700.83
Date Published: 4/5/2010
Language: English
Download here: http://www.microsoft.com/downloads/details.aspx?FamilyID=cfc103b8-7185-4721-8098-110885fe9e9e&displaylang=en
Message Queuing 5.0 Management Pack for Operations Manager 2007
Quick Details
Version: 6.0.6700.88
Date Published: 4/5/2010
Language: English
Download here: http://www.microsoft.com/downloads/details.aspx?FamilyID=28349b78-8329-44aa-8a1f-81f4e3f84d0c&displaylang=en