Some companies announce their new games at big shows such as The Game Awards, E3 or PAX. Some companies announce their new games at online only events such as a Nintendo Direct or a State of Play. Other companies just tweet it out of the blue on twitter. That is exactly what Riot Games did.
Riot Games VP Greg Street took to twitter saying the following, “I have news! My recent job at Riot has been to help develop the League universe, which we’re going to need! Because it is time. My new job is to kick off a big (some might say massive) game that many of you, and many Rioters, have been asking us to create. PS We’re hiring!”
When a fan asked him for more details, Greg responded saying it is an MMO, as seen in the tweet below.
That is all of the details we have. I would expect it to take heavy inspiration from World of Warcraft, considering the fact that Greg was one of its lead designers. As far as when I would expect it to release? Well, lets just say that I am not expecting it to come out before I graduate college (which is over three years away).