Well. This is really quite smart. Apart from the tight grouping, which is just there for the screenshot.
It seems pretty cool so far, with a couple of reservations, mainly around being able to "do something" through the GUI bit that doesn't immediately seem reversible - like when associating items with another class. Initial discoverability was also poor - I had to hunt for something I thought might have been there, after realizing that the Application Diagram Was Not What I Wanted. Wonder if I can go between one and the other easily...?
Anyway, seems that when combined with rapid item creation via the Class Details view, there's not a lot you can't do, and quickly - I dig the "data entry" method of creating classes and methods.
As someone who tends to think visually, I find this much more helpful than the earlier iterations of the class designer, though I'm 72% sure I wasn't using it right in the first place. *shrug*
All up, a nice job by the Class Designer folks.
As my test case, I'm taking another crack at PasteOff in .Net 2.0, having realized that one general profile with an upload and clipboard toggle isn't really enough (as I always need exactly the opposite settings/image format from what I've preselected).
I expect to have it unfinished by about December this year.