In Vaadin 6, you had to invent implement bookmarking, view management and SEO yourself. It is still fully possible (and much easier) in Vaadin 7, but now there is also a ready made high level view management API available. This makes dividing your application into logical views much easier.
Google Web Toolkit built in
This is a huge topic by itself, so I wrote a separate blog post about it. There is also a dedicated page explaining what is going on. Take a look.