Yes they can live happily together on the same PC. You can even use them on the same folder if that makes any sense to you. But, remember, that if you'll commit from this folder using one of the two, control files from the other system can be also accidently added to repository and versioned.
To avoid this problem for subversion you should run a script that does svn propset svn:ignore -F .cvsignore . in all project directories.
It can also happen that some of the overlay icons are not displayed. See also:
The overlay icons appear, but not all of them