If it seems too good to be true, it probably is I'm sad to hear it isn't going to work out with LUA in the future of RW. Because I'm in current state unable to do anything with JAVA. One big reason I found this game interesting, is being able to maintain LUA scripting myself. I see you logic reason for this change, but still it did kill some of the fun here.
Added JAVA to my to-do-list!
Haha! don't be melodramatic The change is hardly too good to be true, but is actually a great news! Lua, while indeed really easy to learn and use, is only adapted for small features. Even the AreaProtection is reaching Lua's capabilities without affecting the game too much. As for WorldEdit, it does cause the server to hang at times when executing some commands. This could easily be avoided in Java.
You perhaps need a little more setup for Java (i.e. installing eclipse and creating new Java projects, etc.) but once this is done, you benefit with a strongly typed language (you always know any variable's possible content), auto-completion, debugging tools (i.e. you can avoid many issues even before launching the game, even create independent tests for quality assurance..), have access to the entire game's feature with direct access to any method (i.e. functions) as opposed to an API wrapper for Lua which rely on adapters (i.e. extra calls and data conversion layers), and have access to the entire Java API such as sockets, file I/O, threads, system's hardware, and the RisingWorld's GUI library.
In essence, this change will not affect current worlds. Clearly, the positive outweigh the negative here. And if no one does it, I will personally make tutorials to help anyone get started easily.