Udi Dahan briefly chats about MSMQ on his blog and provides a useful link:
Microsoft has put MSMQ in the Developer Preview of Server 8 (as Brian Buvinghausen has written here).
There’s good news on Brian’s blog:
“Finally! Microsoft added MSMQ to Server Core in Windows Server 8”
So it will be interesting to see how they got round the limitations of previous versions of Windows Server Core.