Critor has posted news about OS 3.1 for the Nspire here.  For now you have to use Google Translate to read it unless you are French.
Google translate gives the following:

If TI continues its pace of semi-annual updates for the TI-Nspire, a new OS due out soon Nspire, perhaps this summer if the various disappointments of OS 3.0.1, fortunately eliminated rapidly following the release of OS 3.0.2, have not delayed. But we already have exclusive information about this future OS. In late May , confidential documents TI were available on the Internet. They included an English-language literature of the different instructions Lua language. But some of these instructions is apparently not present in the OS... A closer reading of the document reveals that these instructions were scheduled for a future version of the OS Nspire and gives us even began Number: 3.1. One of the new OS 3.1 would be the addition of new instructions Lua.

Also, following up on other astounding PRIZM projects, MPoupe has released a CASIO PRIZM video player, although in its early stages, it looks very good.  You can find the discussion topic here.

This is looking really good, nice job MPoupe!

And concerning the OS, I think it really is important that TI launches a new OS with fixed bugs...

will OS3.1 improve the lua programming?

Yes, it seems like it will add some new functions.

really? like what ?

We don't know, but I which they implemented "io".

I don't think that will happen, it will give developers to much power (in TI's eyes). But it would be nice anyway

IO is a library that provides access to files and to the console.