Calling it now: Bard will be a flop!
EDIT: 35.21% winrate, CALLED IT!
I was super hyped for him, then I played him. Simple to say: Hes not worth it.
Because of RIOTs "pseudo passive" moral, his auto attacks do no damage at all when you have no meeps ready (no kidding his base damage is somewhere around 45, I get exact numbers when PBE is back up), and the damage only gets good after an insane amount of chimes, which would requier him to leave his ADC alone for nearly all the laning phase. On top of that, since the chimes give him Mana and HP back, his base stats are horrible. His Mana pool is a joke and so is his HP pool, same goes for his base reg. (again, exact numbers when PBE is back).
As we all know, reg Items are now based of the base reg a champion has, which means, right, they are basicly useless on him. He has to get Chalice of Harmony ASAP or hes litteraly useless in lane after one fight. Or, again, he has to leave his ADC alone. Forever...
His Abilities are fine, and they are fun, but all what I listed before makes him very hard to play, and seriously, unless you are planning on collecting chimes for like 20 minutes and pray your ADC ist totaly destroyed 1v2 bot, he has nothing that makes him worth picking over other supports, and his horrible stats dont allow him to do any other role.
He needs some serious changes, or hes release urgot/Gankplank/new Veigar Tier.