To my mind, the Bard should be a JOT. I'd design a 4e Bard as a hybrid class, Arcane Leader/??. In keeping with the 4e 'two paths to start with' design, I'd say a Bard could choose two 'styles':
Master Showman (Arcane Controller/Charisma): You can dazzle, amuse, and entertain. You can hold enemies entranced, or shatter their bones with sonic blasts. Music is a living force to you, and you can change the song of the world, causing the very land itself to match itself to your tempo.
Laughing Scoundrel (Arcane Striker/Dexterity): By means of illusion and stealth, you can flit around the battlefield, always glimpsed, never seen. By playing the fool, you can draw close to foes, who do not consider you a threat until you strike.
The buff/healing abilities will be about half of the bards powers, and they will match Warlord or Cleric powers for effectiveness if not style. The bard can then choose ether controller or striker type powers, but splitting up too much would reduce general effectiveness.
At first level, a Bard can pick any at-will ability of any other class as an Encounter power, to reflect their diverse training. They can do this again at Paragon and Epic levels.