John Lance wrote a couple of days ago about how cool it is that in the next release of Lotus Notes (8.5.1) You will be able to access calendaring functionality from the preview pane of your mail. This is indeed a very welcome improvement and being able to accept or decline a meeting without having to open the invitation or your calendar is great and will save time.
But personally I am more pleased to see this innovation. If you have a message that has been archived (as can be seen by the little "torn paper" icon next to it) there is now a button in the preview pane to say "Open in Archive". Obviously this was always possible using the "Open Archived Document" in the Actions menu but putting it as a preview button (also there when the message is opened) is far more intuitive. It is only a little thing but these things really matter.
*As always these things are subject to change