I think it would be a mistake for the Yankees to make Curtis a leadoff hitter. That's not what he is. And, while he's got speed, he doesn't have Michael Bourn or Carl Crawford or Ellsbury type speed. If Curtis is given some discretion to run, which he didn't have for the most part in Detroit, he might be able to be get 30-35 stolen bases. But, he'll get picked off a good 15-20 times in the process.
Curtis strikes out basically once every 4 ABs and hits around .270 for his career. He's not the ideal leadoff hitter. In fact, his ideal spot in the Yankees line-up is probably as the #9 hitter. They might try to make him a #2 hitter though. I'd keep Jeter at lead-off until Curtis proves he's improved on his strike-outs.