i onlly played with one on my team once, and one on the enemy team once and i do not find him anywhere near op. he is a floating ball of utility for sure, but hey thats prime for a useful support.
there are many ways i see his ult being used, most of which i could tell were completely unintentional by the two guys i had last night, but i see a lot of potentional, but nothing so strong he should be pick banned. i mean its another zilean, with 0 damage.
a few notes on cool things you can do with bard.
starting health packs: follow your jungler to his starting camp: drop all you can there, recall and head to lane. Damn this is hot for the jungler!
ult: stop dragon, baron: obviously
save team from devastating ult/incoming damage
probably less obvious: zhonya enemy team
uses: put tanks and front line on pause in team fight while your team freely deletes enemy damage dealers
pause enemy team/2-3 seperated members to give your team enough time to get in position to squish them
pause enemy team to give your team enough time to respawn and defend inhib-turret-nexus
and again pause them for disengauge
with all that, hes not op, he is utility out the pooper.