Apparently, CS3 will be released in pieces, starting with violins, probably next month. A good place to start, as it's always the violins that are the best indicator of a string library's quality, especially the solo instruments.
The new vibrato control should be frickin' awesome for solo violin. Reading through the change logs for past TVEC versions (TVEC = Total Virtuoso Expression Control, what they call their scripting package), a major focus of every revision has been to improve vibrato control. It's the holy grail of realistic-sounding sampled strings.
Longtime KH users assure me there's always been an upgrade/intro offer on new products.
Day 2 of the download. It's been running for 20 hours now and I have 8 of the 34 files. Wednesday was apparently an overly-optimistic ETA.