Something I noticed while watching the recent vid...
It seems the side guns on the AT-ATs don't shoot evenly. Specifically check 0:30 and 0:43 - you will notice the side guns moving, but not shooting. Should anything be coming out of them (I'm not saying they should be constantly shooting, just when it appears they are being used and aiming at something)?
Also, should Wedge's snow speeder cast a shadow at 1:28 when he's circling around the legs in the high overhead shot?