The new Cubase SX2 is apparently ready. There is a lot of info about it at:
Basically it uses the same audio engine and code base as Nuendo, minus a few post-production features. There is a whole bunch of videos on the site and a PDF file listing the various new features.
As well as using the Nuendo codebase, SX2 also incorporates the type of extensive MIDI features that were present in VST (SX\'s predecessor). There is a new routing facility, improved mixer views, a (limited) skin facility, definable outputs, more scoring function, a \"time warp\" tool that works by letting you move bar positions or timecode at will, full plugin delay compensation, surround panner, an interesting set of pan types that lets you control width as well as pan, OMF import/export, etc.