My jME 3.0 correctly handles accented characters like Ä Á À Â. See this post: How to make niftygui to support chinese? - #31 by Ogli
About Chinese characters I don’t know, since the Chinese people on the other thread did not reply to my post.
So I wonder what LWJGL3 will add on top of that.
Btw, TestBitmapFont.java was a nice inspiration for my SimpleConsoleAppState. It’s part of that tutorial game and really works nice for all console commands that I needed so far. 