At the moment, corporation (or alliance) projects are only useful to track a common goal of some sort, but do not allow for the corporation or alliance to return a reward of any kind to its members when they contribute. Therefore, it’s pretty much useless.
There needs to be a way for corporations to setup some form of reward for contributing to different goals. The rewards could be in ISK (per unit of items contributed, such as material or specific items or in the form of a tax return for missions and such), or items (i.e. modules, implants, boosters, ships, etc…).
That would be extremely useful for example, for large mining operations where every members could simply dump their ore in the corp project’s hangar to automatically be paid in ISK for a set amount per unit, until the limit has been reached. Or for a PvP corporation to provide rewards per enemies of a certain enemy corp’s ships destroyed, and such.
That would completely change the dynamic of the game by allowing corporations to basically create content and something clear to do for their members.