So I got the dl code for the demo in Europe, after trying it out, I've noticed some weapons I used to be good with, I'm not doing that well, either because of the new terrain or changes.
For one, the bow now changes between Aim mode with X and you charge shots with R, after using the bow on MH3U so much I keep confusing the buttons. I have notice that instead of Arc shots you have power shots, after fully charging and firing a normal shot, pressing A will fire a power shot right after it.
The Sword and Shield also doesn't do the leap and is instead a running slash, which looks awesome but offputs my timing.
Now one weapon, the Switch Axe, I think as been improved, it plays largely the same but the sword mode X combo has an added quicker slice to it.
I love the Charge Axe, but the Insect Staff I'm not so fond of, I need more time with it to get accustomed to it.
I've yet to try out any of the other old weapons for their changes, but I'll be doing that soon enough.
Also you can fight the Gore Magala in the demo... It's a tough lizard.
I know the demo isn't out in USA yet, but I do hope that NoA gets on to that ASAP.
(Please don't hate me, I just wanted to share my experience with weapon changes D: )