I don't think Soraka's ult was much of a problem but that's just my opinion.
Soraka's ult didn't heal for too much, but it's cooldown was so low that it was always up whenever there was a fight. She doesn't have to choose to use it, she just uses it whenever anyone fights and she can stack assists. Now she'll have an actual choice to make: whether to get some easy assist gold, or to save her ult for a desperate situation.
--
"What if you just eat vegetarians?"-neonreaper
"^ You are what you eat. ^_~"-Koiji