MU rebirth has concluded its second Beta period. I don't see any news about its upcoming 3rd Beta. That's understandable though. I usually play MMORPGs on beta and most of the time, we help the developers improve their game. Like the last one I played: Eclipse War Online. Games like that has tons of things that needed attention. Both of them (MU and EWAR) has been released before. So in a way, it's like testing the waters first. They check how many users logged in, collects feedback from beta players and it might take take a few months to relaunch coz they need to consider some changes. The most fun MMORPG I beta-tested is Ragnarok Online. When it was first launched, the number of players reached 15K+. And that's just 1 server (Chaos). The lag is horrible but still fun nonetheless.