I’m using Movable Type 4 Enterprise. Can I upgrade to MT5?
Movable Type 5 Enterprise will not be available until we complete our rigorous scalability and performance testing on it. We expect MT5 Enterprise to be available in the first half of 2010. In the meantime, please be sure to update your MT4 Enterprise software to MT 4.33, which contains all of the latest improvements in scalability, performance and security.