As far as developers are concerned, they won't have any problem adjusting to a different version control system that is compatible enough with CVS. As for development tools, integration with them is a nice thing, but not a must to use such a tool. (you can always use the command line).
Having used CVS before and using Subversion now, I can tell that I find CVS extremely painful to use now. I wouldn't recommend it for anything. I think we will eventually see CVS superceded by something else entirely, and one is advised to join the switch sooner than later.
CVS - Die! Die! Die!