Honestly, as a fan of Diablo mechanics (though I like the first more than the second, and I refuse to buy 3 due to Blizzard business practices) and super heroes, I'm excited for this one. It's not an MMO, but it looks fun.
I played LoL for awhile, and yeah, its not an MMO. You can call it a deathmatch game, compare it to whatever you want, but the genre that sprung up from the tower defense/tower invade hybrid (even if LoL has a second maptype that was fun for me until a match that... oh god, that was why I stopped playing at all) with that sort of a play structure is "MOBA" for multiplayer online battle arena, which could apply to a lot of older games too.
I remember purchasing the extra rune pages, a couple of the champ packs, and Leona when she was brand new. She was under no tables, so oh the wait on that...
But yeah, this game isn't an MMO. I'm not excited because it'll be a replacement for CoH, but because it'll be a fun game that fills an itch I've had for awhile, and lets me play as Ms Marvel. I've watched a variety of the gameplay, and a friend gifted me the Avengers founders pack, so I'm eagerly awaiting it.
The fact that its F2P with an implied heavy ability to play the game and unlock loads of things for free means that a lot of the money model will be based around things not being droppable at first and or people with less time to play and or exclusive buy only content. This is good for gamers. It lets people who don't have the money for a monthly sub play and even unlock things that others would pay for. But people with money and no time? They support the game they like, and get stuff they want.
Really, this is win win as long as its fun, and it looks very fun.