When working on Component Based solutions one could have multiple (5+ in my case) projects open. It is easy to get lots of open projects in the (Windows..) taskmanager.
To provide better control across this project navigation, it would be helpfull to have multiple projects open in the Mendix Studio (like this is possible in Eclipse).
(I do not underestime the technical challanges here..)
Good idea, I would imagine that this would also make it possible to easily copy & paste items between projects.