I said earlier than it seemed likely that archaic hominid living in special environments, for a long time (sometimes more than a million years) inevitably developed high-quality adaptations to those environments, and since such alleles are easily transmitted, modern humans were likely to pick them up. The recent discovery of a Denisovan altitude adaptation in Tibetans fits this model.
I also said that there was a specific suite of changes favored in dense tropical jungles (Pygmification) and you might expect to see adaptive archaic alleles there too. Mike Hammer and others have an abstract out in ASHG 2014 that supports this notion: there was already evidence for introgression from a very divergent hominid population in Pygmies and Bushmen, and they found some genomic regions that A. look archaic and B. seem to have been favored by positive selection.
There is a good chance that we will find archaic variants involved in Negritos (probably Denisovan in origin), Ethiopian altitude adaptations, and Bushmen ( steatopygia?). Could also occur with less-visible traits such as resistance to regional infectious diseases outside of Africa (such as scrub typhus in the tsutsugamushi triangle).