This is the first time I comment on a film I haven't seen.
Not that I didn't want to. I bought the Disney Treasures/Mickey in Color 2 DVD set, official edition (not some bootleg) here in Germany. I watched Leonard Maltin announce it in his intro, including a second of snippet.. I watched all 5 hours of the DVDs, bonuses and all.. tried all the menus for hidden Easter eggs.. no luck.
As I've met possible censorship on another Treasures DVD just some days ago (Der Fuehrer's Face was missing from Chronological Donald 2 - possibly because displaying swastikas is illegal in today's Germany), I suspect a somewhat similar reason here.. not law, but viewer clearance. The whole Disney cartoons are cleared for age 0 and up. Now if a DVD contains just one item with a higher limit (6/12/16/18), it must display that clearance for the whole bundle.. I suspect that marketing considerations led the German distributor to self-censor and remove Runaway Brain, even though announced by Maltin. I'm really frustrated.
Update, July 11, 2011: Now I've watched the film, on YouTube. A nice combination of modern-day dynamics in cartoons with many 1930s themes: the ancient looks of Mickey and Minnie, the King-Kong, mad scientist, brain transplantation themes and so on... very likable! I was surprised that it was produced in France, but hey, that's globalisation...
So I'm softening my above point on censorship, too. It certainly exists, but given the Net, there just as certainly are ways around it. By the way: some weeks ago, I also located The Fuehrer's Face on archive.org.