I think all freemiums now should be grandfathered in so they get to keep their freemium, but I think a certain date should be posted and from that date on all freemiums should get one month free only.
This would create good business for CC as players become attached to their screen names.
It would also prevent a lot of players that have no business playing for whatever reason you want to come up with.
Down side is more free accounts would be made up after the one month time limit runs out.
I think one month is plenty of time to try out a product. Again, all existing freemium accounts should be able to stay freemium and if your one year membership runs out you should be able to stay freemium.
This is my suggestion-you may or may not agree and you may or may not like it.