Like a month ? just to see how it goes as beta? With bans and every champion unlocked. You can make announcer voice to sell it in, plus e-sports are kind of dying on it's own anyways so it's not like it's going to kill SR.
Do you want 50 billion ARAM accounts? http://img10.deviantart.net/9d20/i/2012/226/f/a/sterling_archer_by_drweb70-d5b24hk.png Cause that's how you get 50 billion ARAM accounts.
Ranked ARAM would be great, but I'm not so sure about doing a month-long test for it. Partly because, with only a month, there might not be enough time for players to play enough games for even semi-accurate ranks. Partly because there's a number of potential ways to implement "Ranked ARAM," and judging the entire concept off the performance of one version might be questionable.
