"The server must be running MOSS2010 to synchronize external list with SharePoint workspace"
I have faced this issue both in Escrow and Beta builds so thought to share it with others to make it easier. If you get the error message or having issues while synching your external list to client tools like WorkSpace or Outlook, then you might need this fix.
This issue prevents connecting external lists to Office client applications on x64 client machines where VS2010 Beta 2 is installed. The issue is due to the mismatching versions of SQLCE installed by Office and VS2010. Office installs x64 and x86 SQLCE and VS2010 upgrades the x86 SQLCE to a later version however it doesn’t upgrade x64 version. When the client machine is in this state, you cannot connect external lists to Office client applications. To resolve the issue, x64 SQLCE should be upgraded to the same version by downloading and installing SSCERuntime-ENU-x64.msi from http://www.microsoft.com/downloads/details.aspx?displaylang=en&FamilyID=411ba1c5-ba57-45b6-9148-91bed6e7a9f1#tm.
Most probably this issue should be gone with the later builds of VS2010.