I agree about opening multiple solutions in a single running copy of VS, although I would only want to do that if 1) it saves overall memory from running muliple copies of VS and 2) if it was easy to switch between the solutions. I assume that if multiple copies of VS are running it does not need to load the same assemblies into memory which takes up more memory. But I would not want them to attempt this if it complicated the IDE too much. I know they are already juggling a million features. I will take performance and stability over a few more features.