Does anyone know if Overwatch comp leagues exist yet? If so, which ones? If not, do we know of any up and coming leagues that plan to support it?
Back when I played console games competitively you could "rent a server" where it was basically a console with a really good connection hosting a private lobby and then the players join it. Entirely possible to do in this game, although without a dedicated server the PCs they would use would probably have to be pretty decent and therefore pretty pricey.
I don't think that's an option - Blizzard has confirmed that all games will be played on their own dedicated servers
Given that, I'm not sure that ESEA will pick up Overwatch - their entire model is based on offering a better competitive experience, which is heavily driven by their client and servers. I believe they have tried it before, with a League of Legends Open division Seasons 13 and 14, but that clearly fizzled out and I don't think they'd be very interested now given how much they're focusing on being the leader in CS:GO.
I almost certainly remember ESL putting out a tweet a few days ago saying something along the lines of "Let the countdown begin" and a picture of the Overwatch logo, or something to that effect. It seems as though they have deleted it since then.
I would assume they'll pick it up in some form no matter what. ESL has, at the very least, Go4 Cups every Sunday for just about any game that has a pulse of a competitive scene (CrossFire, Guild Wars 2, etc). Assuming this ends up being a pretty big game I think its safe to say there would be more than just weekly tournaments.
ESL already got a shoutcast project for the game and I'm sure we'll see Go4Overwatch style cups for the game, with weekly prizes and a monthly final.
Another one that will be sure to pick this up is Zotac Cup, they have been doing cups ever since it was all about WC3, SC2 and QuakeLive, but recently they are just focusing in the Blizzard games and I don't know how they'd miss out on this. For Heroes they seem to give 50€ per player so I'd expect 300€ in prize for Overwatch?
I'm expecting other small tourney organizers like Gfnity to also pick this up.
Talking about big leagues, Blizzard will create their own circuit for sure and I'm expecting DreamHack to jump on this. And the Korean eSports Association (KeSPA) has tight relationships with Blizzard and lately promoted really heavily Hearthstone and Heroes in Korea, so I'm sure Overwatch will be the same. And despite popular belief, Koreans love shooter games (the 2nd most player game after LoL is a CS 1.5 clone) so its popularity there will just depend on the business model for PC Cafes.
Soooooo, TL;DR: I would expect 100% ESL, Zotac, DreamHack, KeSPA/OGN.