Graphical diff's result presentation would be very
useful. Such feature is available for example in ViewCVS
system which is used by SourceForge to display
projects' CVS repository.
Files changed since last commit may be marked
(filenames displayed in different font etc.) in Project
Manager to make it easy to figure out which files
probably should be commited.
For more cool ideas about CVS support and much more
see IntelliJ Idea - perhaps the best Java IDE over the