Following the release of Forefront for Exchange Server with Service Pack 1 (download here http://www.microsoft.com/downloads/details.aspx?FamilyID=2ceb14d4-404b-4d8f-8a21-ebfc71b2e82b&DisplayLang=en) a new management pack for monitoring this is available for download here    http://www.microsoft.com/downloads/details.aspx?FamilyID=1b4e7d52-c550-4dd7-a11f-2c4029b93451&DisplayLang=en

The equivalent MP for Opsmgr07 will be releasing shortly.