The map I played (Utapau) was large, and I didn't run into any situation where you get the 'Traitors will be shot' message for leaving the battlefield.
The new Clonetrooper classes are cool, but the heavy trooper's chain gun takes a second to load, then when it fires you can't control the aim. Basically it locks in on a target, including if you accidentally charge up on an ally.
I unlocked Obi-Wan for a few minutes, and he was cool. Lightsaber moves are limited, there was no advanced control like the 'Sith' game. Pretty much block and slash. Jumping feels a little bit off, but the new roll feature is cool.
The battle really drew me in, and it was pretty chaotic. It should be awesome if they manage to pull off 64 players online.
There is also a teaser vehicle level - the Battle of Coruscant. It was...breathtaking. To be in a Republic fighter and zooming down around the Droid control ships is exhilerating. It's not as easy to crash as the previous game, the control scheme feels more like the Rogue Squadron series.
This game will be a must buy for Star Wars fans, but it doesn't come close (at least in demo form) to Battlefield II. If they tidy a few things up for the November release we should be in for a treat.
However, and this is a big one. Why Lucasarts didn't release this as a 360 launch title is beyond me. You could have squeezed way more into the game and the improved graphics would have been welcome. This just seems now like an extension of the original - almost an expansion pack.
It seems as though it might have been rushed to coincide with the release of 'Sith' on DVD, much as the first Battlefront was to the OT DVD's last year...
See you online...