One thing I would find real handy would be the ability to add a class from another project using the + tab in the top right hand corner. You can obviously cut and paste a class in but I reuse a lot of code so being able to do it without leaving the current project would be outstanding.
There has been talk about a localized code repository that would accomplish this. I think @Simeon has mentioned it a few times. I reuse code a lot and this would be extremely useful to me.
+1 for this idea