i have, and i don't think i have read a solid post that answers this question as it pertains to the internet, different classifications, and a general term, such as "face" gaining trademark approval.. I feel this question i stated above has many facets that should be discussed....
I think what Jeff was saying is that reading the thread will give you a bevy of insight, the first of which being, you can recieve registration for just about any word that 1) isn't merely descriptive (of the goods/services), and 2) does not cause LOC with previous registrations (or previously pending applications).
You'll surely admit that the US is replete with major corporations using the same mark: continental tires, continental airlines; monster.com, monster energy drink.
They have those marks because somewhere along the way someone said "no LOC". Same goes for facebook. "Face" is not merely descriptive for a social network.