Just installed my shiny new copy of Visio 2010, and had a play with some of the UML tools in it. They’ve got a nice new diagram layout feature (heck it might have always been there but the ribbon revealed it to me), and it is really good, you can preview different layouts, and then choose which one you want to go with, and it will organise your class diagrams etc. This would be very helpful on large projects.
Good on ya Microsoft.