(Oh! Forgot to mention that Vetter looks like it's shaping up to be a really great enterprise product!)
And have you looked at any ways to gamify Vetter? I'd imagine that having your ideas socially validated by your peers by itself would drive great engagement, but is that something you've considered?
Have there been any issues with the star rating system? I've seen that a lot of times users will tend to automatically avoid low ratings unless they have strong negative feelings about what they're reviewing: people generally just don't like to be mean.
Have you guys considered an upvote-only system (cf. Facebook, Quora, HN)? That removes the stigma of negative reviews, reduces the number of ratings that are inflated by sheer politeness, and still gives quality ideas prominence. Plus it's strict positive reinforcement (generally more addictive than negative feedback) versus no feedback at all: rather than becoming discouraged from low-star ratings, a user should be more motivated to create an idea that his coworkers respond strongly and positively to.
And have you looked at any ways to gamify Vetter? I'd imagine that having your ideas socially validated by your peers by itself would drive great engagement, but is that something you've considered?