Microsoft announced today (via the DataPlatformInsider blog) that Katmai, AKA SQL Server 2008, will have a feature complete CTP released in Q2, with the RTM release planned for Q3. This doesn't affect their plans to include SQL Server 2008 in their launch of the new "platform" (Windows Server 2008, Visual Studio 2008, and SQL) in Feburary. Check out the blog for more info.
There are some questions bouncing around the internet about what impact this may have on customers. And the fact is, it will have very little. Many organizations are still migrating from SQL Server 2000 (or even 7.0) and will simply have to change their timelines a little bit, and decide whether or not they should move to SQL Server 2005 versus 2008. Couple this with the naturally slow migration process for migrating a company's data to a new platform, a delay of a few months will have little impact. Though it's always nice to hear what everyone out there thinks; please feel free to leave comments and let us know what your plans are!