I don't see Williams' long term future on the wing, but he was good there today. So far in his career at Manly, he's had two games. One terrible, one good. Today he showed Manly what he is capable of, and that is exciting.
Bani hasn't played his best footy this year, but I think he came back from injury early to benefit the team (in round one). He came back quite a few weeks earlier than expected from a shoulder injury (suffered in the finals last year), and I think he's been a bit gun shy because of it. Think back to 2007 against the Dragons when he busted the line off a kick (may have even been a kick-off?) for a Brett Stewart try. It was excellent, and he backed up a few weeks after that when he busted through the Cowboys defence in the semi final and set up Willow.
He has it in him. The fact that he hasn't shown it so far this year suggests to me that he hasn't been fit and doesn't have confidence in his body (probably similar to Williams earlier this year with his hammy's). Bani will be a good first grade winger (for us, or for someone else). I don't know where Williams will end up in our team, but if he delivers more games like today, then I'm more than happy to stick him on the wing for a few more weeks yet!