you can (but are not required to) uninstall your cc versions. the cc 2014 versions do not require the cc versions to be installed, but there are no problems if both cc and cc 2014 are installed.
so, it's your choice. but there are features/capabilities in some cc programs that did were not added to the cc 2014 programs so i'd recommend leaving both for a few months. if you find you have no need for the cc versions, you can uninstall them then.