It seems like it's resurrected in some way or another.

I'd checked in to a Doubletree IIRC in early January 2014 via Foursquare and got nothing. Then, I found the posts here about what happened to Topguest.

Today, I did the same thing at another Doubletree (the one I normally use) and shortly after received an email w/the subject "You just received 50 Hilton HHonors points from DoubleTree Social Rewards". Hmm...

Looking at my emails, the last one I got from sender Topguest was from 6/2013 w/the subject "You just received 50 Hilton HHonors points from Topguest".

The ones I received today, 11/2013 and 10/2013 were from DoubleTree Social Rewards w/the subject "You just received 50 Hilton HHonors points from DoubleTree Social Rewards".

In looking at my Hhonors account, the last time I received a "DOUBLETREE TOP GUEST CHECK IN BONUS" of 50 points was on 1/29/14. Not sure if that the check in was the one from early Jan 2014 w/a huge delay or some other one.

I also received some late last year on these dates:
03 Nov 2013
14 Oct 2013