You know, not mentioning anything on the forums is a good point, and I think I was just so busy at the time that I simply forgot!
With that said, we did post about it on our blog, twitter, and facebook. There was a sale on A World of Keflings that same week, and plenty of press releases and articles from different web sites. Although it's true that "The Curse of the Zombiesaurus" was a bit of a surprise launch, the candy-themed DLC "Sugar, Spice and Not So Nice" has been in production for several months, and it has had plenty of press about it.
I'm sorry if you missed the press, but hope you are enjoying the DLC!