Here's a complete list of what we'll see from version 1.2:
No. 1: Boss Rush Mission
Beat the game to unlock the new Boss Rush mission! Get 1000+ Kudos during Boss Rush to hear the English version of Beyond the Blue!
No. 2: Brand New Lumen Song
Lumen’s brand new song “Sakura Efflorescence” now plays during normal mission playthroughs!
No. 3: Support for New Nintendo 3DS™
Use the ZL Button and ZR Button to change your weapon on the fly! Enjoy higher CPU power and shorter loading times too!
No. 4: Transfer Your Save Data from the Demo Version
Transfer save data from the demo version (coming this week) to the full version while retaining all items and credits!
No. 5: Various Bug Fixes
Various big fixes have been implemented:
– A bug that prevents players from progressing mid-game has been fixed
– Typo fixes
– Other small bug fixes
What's more, Inti Creates are planning to release a 3DS Home Menu theme on titled “The Sumeragi 7” featuring the seven Sumeragi bosses on the top screen and “Sumeragi Skirmish” playing in the background. It will run you $1.49.
Source: Inti Creates