This claim will be judged TRUE if Microsoft releases an operating system with the name "Windows 2000", or an official rechristening thereof, on or before December 31, 1999.
Background: The successor to Windows NT 4, called "NT 5", has been in beta for a while. Its release date has been slipping by relatively large amounts; its codebase is rumoured to be in the range of 40 million lines of code, and Sun's CEO claimed that such a product was "unmanageable". It was recently officially rechristened "Windows 2000".
This claim is not about the name of the system, but about the release of a product that is "built on NT technology". For instance, a repackaged Linux pushed as "Windows 2000" would not qualify.
This claim is an extension of a previous claim, NT599. See that claim for some background on this one. In my mind, the primary difference between the two is semantic; NT599 depended on the release of a product named "Windows NT 5.0" to be judged yes, whereas this claim is focused on the delivery of the logical successor to the current generation of Windows NT products.
The official site tracking the product's release can be found at: http://www.microsoft.com/windows/professional/
For the purposes of this claim, the release of *either* planned version -- Windows 2000 Professional or Windows 2000 Server -- before the deadline will qualify for a YES judgement.