I've said many times here that there should have been more made of the Anakin/Padme/Obi-Wan relationship, like a love triangle of sorts, with Obi-Wan having secret feelings for Padme. It would have made Ben's relationship with Luke even more meaningful- and would have actually added something to the OT. It seemed like such a no-brainer at the time- I was sort of expecting it and was disappointed when it didn't happen.
Yet another missed opportunity.