Team Instaburst has just released a teaser trailer of the fighting game they're making based on LoL, dubbed League of Fighters.
It looks like it will take a long time for the game to be released as it's still in its development stages, so Team Instaburst has called for volunteers to join their dev team and help them in completing the non-profit game for all LoL fans to enjoy as soon as possible.
Sources: Shoryuken.com, Instaburst