Two new heroes announced for Dota 2, one is playable right now
Two new heroes were announced for Dota 2 during The International, and you can play one right now.
Grimstroke and Mars were announced as new playable characters for Dota 2.
During The International this week, Grimstroke was made available to players as a new, ranged support hero. As you can see in the trailer, he wields a rather dangerous rebinding brush dipped in "profane ink."
You can look over his character page through the official website and familiarize yourself with his moveset (thanks, Neowin).
Mars will be added as a playable character in late 2018.
A card game based on Dota 2, Artifact, will also be released later this year in November.