Well we have all heard that ND6.5.1 is due out real soon now and not just for Notes Domino but also 6.5.1 versions for Sametime, Quickplace and Domino.doc. All future version releases will also have the same version numbers and will always be released at the same time so no more having to keep that one server on R5 because your running Sametime.
One feature currently in ND6.5 that a lot of users haven’t really seen yet is the new Workspace style today page. This workspace makes it easy to get to the information that you need on a daily basis quickly. New to me is the ‘Mail Threads’ view. This page is displayed with a large inbox window on the top and a smaller one on the bottom. As you select a mail in the top window it automatically shows the entire mail thread for that message so you can quickly go back to any message in the thread for reference.
Another nice feature in ND6.5 is the integrated sametime contact list. When you open the list ( CTRL-SHIFT-C ) it displays your current sametime contact list but as you work in the notes client and you enter a document with sametime enabled fields it will dynamically update the contact list with the names of the fields and their contents. A quick reference to ND7 mentions that a lot more default databases will be sametime enabled.
Dec's Dom Blog 