ObjectSpaces Functionality to be Delivered with Longhorn "Developers who have been following the evolution of "ObjectSpaces" – a technology effort building services supporting object representations of data in relational databases – will be interested to know that these efforts are being merged with the Windows code-named “Longhorn” object/data technology “WinFS”. This decision was made after evaluating the overlapping scenarios that each of these technologies delivered and firm feedback that developers and architects need a consistent, long-lived API delivering this functionality. More information will become available through MSDN for developers and architects to plan and build solutions today using the .NET Framework while planning for the exciting features of Windows code-named "Longhorn"."
That's a big cut from Whidbey. Lots of interesting speculation about the reason for the change in plans.