Hey! Support for non-roman scripts depends on the font you supply. If your font contains the appropriate characters, then it'll be fine. Here's an image showing a font that contains Japanese characters: http://imgur.com/YagfBi6
(An exception to this is emoji, which seems to get totally messed up in Unity for some reason. Emojis don't seem to work in standard text meshes either, so I'm planning a workaround for a future update.)
As for RTL text, it'll display just fine! But like every text field in Unity, it seems like you have to type backwards, or just copy-paste in the text you want to use. Unity is looking into support for RTL inspector fields in the future, from what I've heard.
Finally, for the animations that read out text, there's currently no support for it, but it's a feature that's already on the to-do list in the docs! So it'll be added sometime soon. I think I might have just come up with an easy way for me to do it, so hopefully it'll be in the next update!