What struck me when watching the deleted scenes for the OT, the sandstorm for Jedi especially, was that the dirt and specks seemed to show up in the same places repeatedly. It almost looked artificial, like a cheap "silent movie effect" loop was run over it.

I know I'm being overly paranoid here, but what if Lucasfilm intentionally added the dirt just to avoid people like us the access to high quality footage of these scenes?

I never bothered to analyse the dirt specks to confirm or deny my hunch, I just revel in the conspiracy theory!

The fact that the clips show no resolution above 720x480 adds fuel to my fire :-)