So SBS2003 R2 is nearly here. "Should I care?" I hear you ask.
Well, on the evidence Microsoft has presented to date, the answer is a resounding NO!

"But doesn't it get me all the latest technology from Microsoft?"
You mean like Exchange SP2, ISA2004 SP2, Sharepoint SP2, WSUS? They're all available for you to download and install on SBS2003 today, for free.

The other benefits of SBS2003 R2 are SQL2005 Workgroup Edition and expanded CAL rights.
Given the current shortage of applications that can leverage SQL2005, this is more likely to be a problem than a benefit. And you can't install SQL2000 instead. About the only real positive is those expanded CAL rights. With SBS2003 R2, your SBS CALs will not only cover access to member Windows Servers, but also member SQL 2005 Workgroup Edition and Exchange Server 2003 Standard servers.