Originally Posted by
Zelta
A Public Test Realm is a realm which its only reason to exist is for everyone to be able to test future content. By making a public test realm prior the final realm we ensure that big bugs / exploits which were not trivial to find (i.e. happening under very specific conditions) will not happen on the official realm; because some of their consequences are not easy to revert.
If we were keeping the first version of the realm, we would be keeping stuff from the people who took advantage of the new not-fully-tested source code.
It is unsure how long it will last at this point, but to make yourself an idea the final realm might be released by the end of the year.