Microsoft officials have said the next version of SQL Server is code-named "Katmai." (They've said relatively little about the product beyond that, but word is there will be an informational update in the next month or two.)
But it turns out Katmai isn't just a SQL-Server-specific term. "Katmai" also is being used to refer to the next version of System Center Operations Manager, too. The next version of Microsoft's client-monitoring product. The final, official name of the product will be "System Center Operations Manager 2007 R2." (System Center Operations Manager used to be named Microsoft Operations Manager, or MOM, for you Microsoft historians out there.)
System Center Operations Manager 2007 is available in Release Candidate (RC) 2 test form at the moment and is due for release this year. System Center Operations Manager 2007 R2 is probably a couple years away, making it a 2009 deliverable, I'd guesstimate. Does that mean SQL Server "Katmai," a product many were expecting to see this year, won't hit until 2009, as well? Stay tuned.
(And if you're wondering about the origins of the "Katmai" code name, it's part of the national-parks code name theme favored by members of the SQL Server team. It's just one of many different Microsoft codename themes I've been tracking.)