I see them as well, and here is a picture:
You see that? The font size is what you find in little disclaimers, the type font size used when you have to say something, but you are embarrassed or don't want people to see it. The font size is 8, sometimes Google bans sites for hiding text in that font size (kidding). Here is a larger picture, full size.
Yahoo seemed so proud over their partnership with Bing. Then why make the "Powered by Bing" so small? Why not link to Bing also? Is Yahoo ashamed that they failed at core search?
Forum continued discussion at WebmasterWorld.