Hmm, isn't the technique being used called vocoding? Or is that also derived from the original analogue thing? I know it started that way but these days a vocoder stands for the technique being used, not being an emulation of the original thing perse.
By the way, if anyone is interested in buying a Digitech Talker (I guess it's the same vocoder technology as the Vocalist), I'm selling mine. Mint condition, only used for some recordings a few years back.