Shapeways will be unmatched until another company can manage the costly task of acquiring an SLS printer army that can match Shapeways collection. ...But it's yet to be seen if their business model is really making good profit yet.

Thingiverse has lots of competition out there. ...I think what will really solidify them with people is if they set it up so that you can sell through Thingiverse. With their current community, if things were thoughtfully priced, there would be a lot of money to be made for MakerBot and 3D builders wishing to sell some of their more prized designs.