Lotus have put together an excellent Flash Demo showing off all the different parts of ND6. If you have to convince anybody to upgrade to ND6 then I’d certainly show them these. It would be nice, however, if you could download the flash files so that they could be used offline when visiting customers.
I’ve also noticed that the IBM WorkPlace Messaging product has reached Beta 3 status. If you have access to the IBM Partner World for Software then you should be able to download the new beta and try it out.