Here’s a Panther walkthrough.
Here’s another (sorry, no permalink to be found).
Panther definitely looks cool. The improvements to Mail will be quite welcome by my colleagues and myself. The new Finder interface doesn’t look that bad; people should stop pissing and moaning. David, who had a chance to see it an action at NECC, said that Exposé is awesome.
One thing that frightens me, though, is tabpanels. They look significantly different in the screenshots I’ve seen. I wonder how weird they’ll make my programs look?