I don't think any of the players on the current team apart from Ganguly are regarded as leadership material. This is because Ganguly has an aggressive leadership - the on field leadership skills may be different and not observable to the public eye. However, this just brings to point that no one is fitter to lead the side than Ganguly.
Dravid is a good captain but he doesn't really inspire confidence - at least not to the general public. Sehwag, judging by the way he plays, may be an over-aggressive captain. Besides, the last thing we want to do is affect his batting in anyway. We've finally found an opener in both forms of the game who can make or break the game for us.
Laxman and Kumble never seemed like leadership material and besides they are not a really happening future prospect seeing that they will probably retire after 2007 world cup or leave themselves to just test cricket. Irfan Pathan too is a great batsman and bowler but he doesn't look like he will be able to lead the team. Captaining a team is a very difficult one (in terms of skillsets - let alone the fact that 1 billion people evaluate your actions). You need to KNOW when and how to change the field, who to bowl, and all that other stuff. Apart from that you have to have an intrinsic feeling as to when to do something.
Hopefully Kaif or Yuvraj will blossom into a leading figure. Kaif seems to have the aggression and the responsibility to fit the job in a few years. Yuvraj definitely has leadership qualities, considering he is the 'fielding captain' of the Indian team. Yuvraj can also motivate the rest of the players exceptionally well. So basically this story is well up for debate, because in the public eye Ganguly seems like the best leadership figure.