If not what did the others reveal?

I think I remember one or two before, but I can't remember what they were about.

I must admit that I don't remember any others.
They've given hints about stuff coming in the future, but I don't recall ever seeing an actual countdown timer here before.

Well, they had a countdown timer for the end of the holiday sale.

Unexcelled? Wut?
*googles*
EDIT: No clue what's the countdown for. (Although, there are games for Excel. Didn't know that.)
Hmmm. Spacey background... Some kind of space sim? Space strategy? Doubt it's GalCiv...
Ah well, 5 days, not far off.

We've already got a random speculation thread going:
http://www.gog.com/en/forum/general/the_countdown_has_started
As for the countdown itself, to my knowledge, they have never done one associated with a publisher announcement before, and it would appear that this must be publisher announcement (countdown ends next Thursday, the traditional publisher announcement day of the week). With the hype a countdown generates, it better be huge.

Indeed there are. The most awesome I've ever seen was a clone of the original Pacman arcade game, where each pixel was a cell, minimized completely, and changing background color accordingly.

Seriously? People go to those lengths? Wow.

Certainly. Have a look at this. Unfortunately the page is in Japanese.