I think it's only a matter of time, soon we will be betting on e-sports
To me this is a sensitive subject. These are games that kids play and these games, like Dota2 has gambling built into it. Which is fine because its done in a way that it can't get addictive but still, this is like exposing a very vulnerable section of society (kids) to the vices of gambling.
Any future where this becomes a mainstay should be done in a way where kids are at least left out of the hardcore gambling system.