It was back in March when Valve first released the Dota Labs feature. It's a way for the studio to test new content and see if it can be added to Dota 2. Ever since that announcement, we haven't really heard much about it.
This was confirmed, in a way, by Valve. The studio revealed in a post that they've been continuing to iterate on the features though quietly. However, it seems like they're now going on the opposite end and announcing what's in the works. For starters, players can check out the high-visibility hero health bars, which can be toggled through Options and then Interface.
