It could be interesting.
One problem I would foresee though, is like very much the Scirra's arcade, the great number of daily submissions could simply "lose" users.
Also, gamers feedback is important indeed, but not necessary always efficient for developers. One gamer strictly giving feedback like "the game ****** is not that useful to a developer. And in case of bugs or something, gamers don't have the reflex of giving the more informations needed.
C2 devs don't even do it (look at most of the requests for help in these forums, it's often missing/lacking efficient infos).
So it could be an interesting idea, but you first need a "good"/informed community so that gamers can still have fun testing games out and their feedback could be really impactful and interesting for devs.