THE OFFICIAL BLOG OF THE SBS "DIVA"

And you can't RDP into it.

So there are a couple of resolutions.

1.  Ensure that you have put the SBS 2003 port exclusions in place after the August DNS patch. 

The Official SBS Blog : New KB Articles Released Concerning Issues Around DNS Security Update 953230 (MS08-037):
http://blogs.technet.com/sbs/archive/2008/07/25/new-kb-articles-released-concerning-issues-around-dns-security-update-953230-ms08-037.aspx

The issue is that due to the new 'randomness' of DNS on the server it will yank ports that the server needs for RDP or IPsec.  Each month that you reboot and don't have these port exclusions in place on SBS 2000 and SBS 2003 you are running Russian Roulette.  It may also impact other services...like Blackberry server service, Quickbooks and so on.

2.  Ensure that you have a script to manually shut down Exchange

Charlie Russel and Andy Goodman both recommend that you manually shut down exchange before patching/rebooting.  This tends to get rid of the rebooting stuck issue.

http://msmvps.com/blogs/bradley/archive/2007/11/17/charlie-russel-on-shutdown.aspx

3.  A race condition with TS that is helped with a hotfix

A Windows Server 2003-based computer stops responding when you shut down the computer in a remote console session:
http://support.microsoft.com/default.aspx?scid=kb;en-us;930045

4.  A condition on the way back up where the RDP listener isn't listening:

RDP clients and ICA clients cannot connect to a Windows Server 2003-
based terminal server after hotfix 938759 is applied to the server:
 <http://support.microsoft.com/?kbid=958476>

5.  Another one with the same issue where RDP isn't listening.  Appears to be fixed by reapplying 2k3 sp2

But if you've seen this issue, you aren't alone.  Some get stuck shutting down, some get stuck starting up.