I was going to get the pack, but the sale seems to have gone.

It seems to be that way. Disappointed since I was coming back to buy it also. I know it's the last day the games are available, but nowhere in the announcement did it say the sale was going to end before they were delisted from the store. Oh well.

This is stupid, why end the sale A) before the games are removed and B) at such a stupid time.

Because they ran out of gum too early.

From the news post: There was even a sale countdown displayed on both the promo page, and on the promo's "banner" which was in the rotation on the front page.

I saw the countdown, it said 2 days 2 days ago.

Yep. It also displayed hours, minutes, and seconds -- did you pay attention to those as well? ; )
The countdown was accurate -- I checked last evening, and it added up. believe me, if the promo had ended earlier than was stated in the announcement, there would have been holy hell raised in the forums; as it is, this thread contains the only complaints I've seen about GOG messing up the timing or whatever.

That said, even if you don't get the games purchased before they're removed from sale tonight, if you poke around in the general forum, you'll probably be able to find someone with a spare gift code for whichever of the games you were gonna pick up. : )