An official translation of some core system changes being made to Ultimate Marvel vs Capcom 3 is now available via Capcom-Unity. Note number 9 is now accurate, and the translations overall indicate quite a few things differently. The original information can be found on the Japanese UMvC3 website.

Thanks to Nyoro for the original translation.

Notes

1 – X-Factor can be activated in the air.

2 – The attack and speed increases for each character while in X-Factor have been adjusted. Additionally, the damage reduction minimum while in X-Factor has been decreased from 50% in MvC3 to 35% in UMvC3, and Hyper Combos performed during X-Factor will now be subject to damage scaling.

3 – An upward exchange (this was sideways exchange in previous builds, and may be a translation error) during an Air Combo will take away 1 bar of your opponent’s HC Gauge.

4 – When you launch the enemy in the air with a Special Attack, hold the button down and your character will automatically super jump to follow the launched opponent. (This can be turned on or off in the Options menu.)

5 – The window for Aerial Exchange Counters has been adjusted, making it easier to land one.

6 – If you land a Snap Back attack on an assist character, similar to the landing it on the point character, the assist will become unavailable for a short period of time.

7 – It will no longer be possible to block during an air dash.

8 – The rate of HC Meter gain has been decreased by 10%, to 90% of what it was in MvC3.

9 – In MvC3, the amount of hit stun caused by assists was fixed, but in UMvC3 hit stun caused by assists will also be subject to hit stun deterioration during combos.

10 – For characters who have 8-way dashes, the speed on their down-back air dash has been slightly decreased.

[tip from Chindogg]