OK guys, you've probably already seen this but I thought I'd repost here, since I think that, although it would be quite inexplicable, it may actually be an intentional change, because it's only the soldiers that are totally blurred and not the AT-ATs:

Adywan just posted this:

http://screenshotcomparison.com/comparison/93945

It's a comparison between the Blu-Ray and a 35mm scan of the original version. The Blu-Ray fails miserably.

Maybe they were trying to conceal the AT-ATs' feet being hazy by making it appear that there was actually a misty haze on the ground level? Because it does look less like the AT-ATs are floating in the air.