Project Attributes

I don't know what the original poster had in mind, but in my workplace, one thing we would be very keen on would be an easier way to track project level information, like Customer, Cost center, project billing type (fixed time/cost or time-bound), and stuff like that.
Right now we'll probably just use a naming convention to at least keep track of the customer the project belongs to by naming them something like <customer>.<project>.

A document or item on the portal should do the trick. If you're interested in tracking a significant amount of metadata around a team project, consider creating a work item type such as "Project Details" and opening new work items to track the info. Of course, this is overkill unless you have lots of details or are interested in tracking the details.