SoniVox (http://www.SoniVoxmi.com) has released the first instrument from their new Nemesynth Audio Research Group: Vocalizer, an US$149.99 vocal production synthesizer.
It couples a new technology synthesis engine with an open input based architecture. Vocalizer is one part effect plug-in and one part virtual instrument. Vocalists, non-vocalists and producers feed Vocalizer any audio source, and it re-pitches, effects, and re-synthesizes the original source into a new sound.
Vocalizer also works well with other types of inputs. Drum and percussion tracks fed through Vocalizer result in complex synth lines that perfectly sync to the original dry drum & percussion parts, according to the folks at SoniVox.