Wildcard has released a list of all the official servers that are being repurposed for post game release servers. If you have a character, dinos, or anything you'd like to keep you'll need to move them to a server not on the list.

It may be a futile effort though since Wildcard has said they're ending customer support for legacy servers (any servers pre-release) meaning they're openly condoning hacking, duping, under-meshing, harassment, you name it.

The removal happens on the 29th.