The next and still unannounced hero coming to Overwatch is going to be "meta-changing" when the community finally gets to see what Blizzard is working on, this according to game director Jeff Kaplan, who said as much to Overwatch Central.
During the interview Kaplan goes through the process of adding a new hero to the game, how they have to carefully integrate that character, explaining that they can't just throw it in the mix and hope that it works. However, it sounds like the studio is quite far into the development of Hero 27:
"It's a very good sign when a hero enters the hero lineup," Kaplan explained, adding later that "it's in every one of our playtests. The new hero is at that point [...] We never test without that hero."
Interestingly, Kaplan points out that as the game gets bigger, it takes longer to add new content, not just because it requires careful balancing, but also because a new hero requires plenty of additional content, such a skins, emotes, and new story elements.
"We are doing things like making skins for that hero, which is a really good sign," he added. "If we were going to change our minds, we wouldn't be making skins or doing that sort of thing."
As you'd expect a new character will impact all aspects of the game, and that's something that Kaplan reiterated during the interview. It's clear that the anonymous hero has made a positive impression on the team, though, as Kaplan said the character was "super-solid" and "meta-changing". We can't wait to find out more.