I believe you are right, the great source is wikipedia on the super hornet says that it flew refueling missions in oifI just took the ASTB on Wednesday, and had the question "what plane did the Navy convert to a tanker during OIF?"
The options were: Tomcat, Falcon, Hornet, and another I can't remember (but I know it wasn't a Viking).
I don't know of any tomcats being used for refueling, and the falcon is Air Force, so I narrowed it down to the Hornet, which I know is currently used as a refueling aircraft .
Boeing F/A-18E/F Super Hornet - Wikipedia
en.m.wikipedia.org