Should beta testing first bring answers to marketing or to engineering?

Alison's contribution:

I'm assuming that your focus groups/alpha tests have already determined what was needed for the longer term - so Mareting have their priorities already. 

I would personally concentrate on getting the product to market as bug free as possible with a suggestion box/feedback for 

"if there was one additional thing you'd like us to release next, what would it be" types of questions/multiple choice answers. That way, both interest groups would be getting useful intelligence.