My company is working on developing a new product that is similar (but larger in scope) than our existing, primary application. It will incorporate most of the functionality of our current application (except where that functionality isn't currently being used) and eventually supplant it.
Our initial thought was to solicit product suggestions and feedback on mock-ups from certain members of our current clientele who have made multiple feature suggestions in the past. This seemed good in theory, as we could get a larger perspective from our projected user base as well as getting buy-in from those customers who might have had feature requests they previously made indefinitely postponed.
In practice what we're getting is a lot of silence. We have meetings with this group every two weeks to get their feedback and suggestions. However, they rarely - if ever - have anything to add. We've tried emailing out to them a few weeks in advance, asking for their suggestions on a certain feature that we intend to design and mock-up for them on x date, and no suggestions come back to us. When we ask for feedback on existing mock-ups during the meetings, the response is always along the lines of "Oh, that looks good...I'll get back to you if I think of any problems." This leaves us extremely anxious.
TLDR: The concern is that while our design may look great to us and our business team, our customer base won't like it (there are many areas it is radically different, based on things we implemented poorly the first time around). Can anyone offer any suggestions on ways we can better solicit feedback?
Edit: Please note that I'm not asking how to proceed without client involvement. Rather, I'm looking for suggestions on how to convince people that it's in their best interest to be more involved.