Since 2005 here in Durham: http://triangleexplorer.com/2012/03/31/what-is-a-locopop/
St. Augustine has Hyppo Gourmet Pops since 2010 and I think KIng of Pops has been in Atlanta for close to a decade. That's only two points of data; still, this isn't that new. Maybe just slow to spread.
Nashville has had Las Paletas for at least a decade: http://www.yelp.com/biz/las-paletas-gourmet-popsicles-nashville
But what does that shop have to do with Pittsburgh?
I thought it was the waffle taco.
Sometimes during the winter at Steel City Pops, you can pay a little extra and have your popsicle dipped in chocolate, which can make some great flavor combos. They're enormously popular here in Birmingham.
All Hail the King of Pops:http://www.gwinnettdailypost.com/news/2013/mar/09/local-brothers-become-kings-of-the-popsicle-world/