Windows Sharepoint Services 3.0 is going to be removed from the final version of Windows Server 2008 and will once again be an installable component from the web. This change has been made pretty late in the game, but this is no difference to the situation we have today with Windows Server 2003.
For people who currently have the RC0 version of Windows Server 2008, there is going to be a change when they move to RC1, but not a significant one. Down the road, this will aid in the maintainability of the Windows Server and the Windows Microsoft Update process moving forward.
There seems to be some concern on the threads ( including this one from Mary Jo Foley ) on the subject, and the reasons behind this? There is certainly no plan to make WSS a product we sell. Its free guys and has been for a long time.