Riot's April Fools joke is pretty great as it's not really a joke. Urf the Manatee has been around for a while, being an April Fools 'new champion' in previous years but this year Urf stands for Ultra Rapid Fire. Riot claims in season 4 they'll remove all resource dependencies, give every champ an 80% cool down bonus and give Marksmen champs huge damage and crit bonuses, essentially turning the game into an ability spam fest. That's pretty obviously the joke but the great part is the 'preview' mode is real and it's as ridiculous as it sounds.
I know Giant Bomb is all about Dota (damn you Brad) but this is pretty great for people who play League.