If healers were defined by their heals, then holy paladins would be the strong, silent type. Our roster of healing spells has always been meek. The three-heal model of Cataclysm and the introduction of our holy power heals definitely increased our selection, but we have nowhere near the healing spell diversity of a priest or druid. We're only now receiving a true AOE heal in patch 4.3 with Holy Radiance's redesign.
Rather than leaning on a variety of healing options, holy paladins like to keep it simple. We're able to compensate for our undiversified healing tool box by drawing on our numerous other abilities. We might not have as many healing spells as the other guys, but we certainly have more utility spells than they could ever dream of. Our "Hand of" spells allow us to go further than any other healer can.