What is the genre of HoN/DotA/LoL?
Solution 1:
According to Riot's official description of League of Legends, available here:
League of Legends is a session-based, Multiplayer Online Battle-Arena game where rival teams compete against one another for victory on highly stylized battlefields and landscapes. Built by a veteran development team and the original creators of Defense of the Ancients (one of the world's most popular player-made mods), League of Legends combines elements of the role-playing and strategy genres with addictive battle action. League of Legends brings accessible, replayable and endlessly competitive gameplay that deepens with the player's commitment.
Bolded emphasis mine.
Solution 2:
The name seems to be simply : DotA (Defense of the Ancients) since this is this mod who made this genre popular.
Wikipedia states that:
Alternative terminologies
Terms commonly used to refer to the Dota genre include but are not limited to "AoS style games" (Note "Aeon of Strife" a mod in StarCraft), "DotA style games", "DotA based games", "Dota games", "DotA clones", "DotA-Likes", "Action Real-time strategy games", and "Action RTS games". Dota games can also be simply referred to as DOTAs.[3] Riot Games has also been known to use the self-coined term, "Multiplayer Online Battle Arena".
MOBA terms seem not widely used and, for the records, is currently redirected to DotA genre on wikipedia.
I think a common agreement is not defined. And in my opinion, this is gonna end speaking of those games as "Dota-likes" as it was for Doom and its "Doom-likes".
Solution 3:
MOBA is the best suited genre of these games if we go by definition given in wiki
Multiplayer online battle arena (MOBA), also known as lords management (LOMA) or action real-time strategy (ARTS), is a sub-genre of the real-time strategy (RTS) genre, in which often two teams of players compete with each other in discrete games, with each player controlling a single character through an RTS-style interface. It differs from traditional RTS games in that there is no unit construction and players control just one character. In this sense, it is a fusion of action games and real-time strategy games. The genre emphasizes cooperative team-play; players select and control one "hero", a powerful unit with various abilities and advantages to form a team's overall strategy. The objective is to destroy the opponents' main structure with the assistance of periodically spawned computer-controlled units that march towards the enemy's main structure via paths referred to as "lanes".
This definition clarifies lot of things. It explains the charecterists of a MOBA game which is matched with all the three games you listed and it also states that MOBA is sub-genre of RTS which valve wants to call its upcoming game, Dota2.