Double Post but the site has fully updated, so here are all the new things the game's getting, this will be a bit image-heavy:
Gameplay/System Updates
Rematch option
As mentioned on the main site "The “One More Game!” mode will allow players who win in Team Battle mode to request to play together again in the next match. If both players request the feature, they will continue onward together."
Zenkai Tag Burst
Iniciated by pressing "Up+Strike+Jump" on the arcade machine, this acts as a new Tag Team attack to deal additional damage to the opponent.

During the attack, if one of the team-mates presses "Start" they can recieve a little bit of health.
Guard Crash
Players can now crush the opponents guard by dealing continuos strikes, breaking the shield bit-by-bit, if said shield is destroyed, the opponent must wait a bit until it comes back (I'm guessing it works like J-Stars in that it's tied to the energy gauge) or be simply knocked down.
Content Updates
Stages
2 new stages were added to the game, these are:
Kaioshin World
Kame House
Characters
Saved the best for last, the new 2 characters are:
Super Saiyan 3 Goku
With attacks such as "Super Dragon Fist" and "True Kamehameha", you wil be able to explode with power.
Super Saiyan 3 Vegeta
Showing his powers, Vegeta brings "Infinity Down Burst", "Big Bang Blazer" and "Saiyan Warrior Race" to the table to show who's the "Real Number 1".
The updated is scheduled to roll out on the 30th,all the information is taken from
http://db-zenkai.com/ver3/news/