The screenshots reveal pretty much what we were expecting, no huge surprises there. We're seeing all the standard configuration options, and the social screen shows ignore lists and block lists in the config section rather than an in-game social one. While the hero abilities are mostly what we had seen already, given that 18 of these characters were playable at BlizzCon, there are five new ones since November. Sgt. Hammer, Tychus, Zeratul, and Muradin are all new, and E.T.C. was not playable at BlizzCon although we knew a lot about him as he was discussed at great length during the panels. The most exciting part of these leaks is the implication that Heroes beta may well be coming soon!
Edited to add: Heroes Community Manage Cloaken posted on Reddit to clarify that the images are legitimate, and no surprise to the team. He also adds a warning about phishing -- be vigilant!
You can check out what we saw at BlizzCon and subsequent Q&As as well as my review of the game, and the gallery below!