Played with V-Vocal tonight..
Its pretty amazing actually.. based on Roland VP technology, I'm not sure how it compares to Melodyne or Melodyne Uno, which I had been looking into, but never had a real need for... This might have solved the issue.
The UI looks like garbage, but its actually REALLY usable, and makes a ton of sense. The fact they integrated it so well into Sonar is a huge reason its such a killer plugin.
I was never into the Logic idea of host + effects + instruments when you buy a sequencer.. but after seeing Sonar5, its changing my mind... Sonar5 now comes with Roland instruments / effects, rgc:audio (cakewalk) instruments, and ultrafunk (cakewalk) effects... Its a pretty deep lineup for 'out-of-the-box' functionality.
I'll post more as I try new features out.