This is made by Riot, not Blizzard. There is no Mac version (at this time). Riot has expressed interest in eventually creating one.

For now, it seems to work well with Bootcamp.

I'm not sure about other programs: I know some others work and some others have problems. I don't have a Mac, so I don't know how much of a hassle it is to emulate these OSs.

The Mac version is not very high on Riot priority list as far as I know. I'm sure they'd value a Mac consumerbase, but as a startup company on their first game, I think they have other things they need to focus on right now. I hear what you're saying about the buzzwave, but I think most of their customers are going to come from the MOBA community and word of mouth rather than smart advertising.

Mac version please!

If you'd like Riot to make a Mac version, I recommend posting it in General Discussion (possibly with a poll option such as "I'd be interested in playing a mac version of LoL" and "I would not be interested".) This will both A: give your proposal more visibility to Riot and B: provide them with a ballpark estimate of the number of Mac consumers.

Again, I don't believe it's going to happen in the near future (many months), but it can't hurt to ask.