They arrived with last night's update, along with a bug fix for Devona, who really wanted to keep "Charge!" on her bar. While it will take some time to get a feel for them in battle, the Live Team clearly had a great time putting them together. The models look great -- a nice variety of looks and styles, and talking to them gives a brief dialogue that says a bit about their personality. In a fun little touch, many of their idle emotes fit their personalities as well. Talking to them will also reveal their skill bars, allowing you to make your selections without resorting to memory or the wiki.
Heroes have been removed for the time being, but don't worry just yet if you want them back. Community manager Regina Buenaobra says, "After yesterday's update our programmer is looking into enabling Heroes in the Guild Hall. He is optimistic that it's possible."
The new henchmen are available in Heroes' Ascent and in guild halls, and while it's a bit disappointing that we didn't actually get henchmen named Hi Captain Obvious or Noodle Legs, we are optimistic that they'll live up to expectations on the battlefield.