WMF 4.0 Preview has the same set of known incompatibilities with existing applications as Windows Management Framework 3.0, as described in the Windows PowerShell blog post at http://blogs.msdn.com/b/powershell/archive/2012/12/20/windows-management-framework-3-0-compatibility-update.aspx. The following applications are affected by known incompatibilities:
System Center 2012 Configuration Manager (not including SP1)
http://support.microsoft.com/kb/2796086 (Configuration Manager Management Points co-located with clients fail after installing Windows Management Framework 3.0 and running Client Health Evaluation)
System Center Virtual Machine Manager 2008 R2 (including SP1)
http://support.microsoft.com/kb/2795043 (Managing Hyper-V hosts using Virtual Machine Manager fails with Error: 0x8033803b after installing WMF 3.0)
Microsoft Exchange Server 2013, Microsoft Exchange Server 2007 and Microsoft Exchange Server 2010
http://blogs.technet.com/b/exchange/archive/2012/12/14/windows-management-framework-3-0-on-exchange-2007-and-exchange-2010.aspx (Windows Management Framework 3.0 on Exchange 2007 and Exchange 2010)
Microsoft SharePoint 2013 and Microsoft SharePoint 2010
http://connect.microsoft.com/PowerShell/feedback/details/746908/powershell-3-0-and-sharepoint-2010 (Windows PowerShell 3.0 and SharePoint 2010)
Windows Small Business Server 2008 and Windows Small Business Server 2011
http://blogs.technet.com/b/sbs/archive/2012/12/15/windows-management-framework-3-0-applicability-on-windows-small-business-server-2008-2011-standard.aspx (Windows Management Framework 3.0 applicability on Windows Small Business Server 2008/2011 Standard)