Tendulkar- He was made captain at the wrong time, and he was not given a fair try. This was the quote of Sir Garfield Sobers, who has been part of a great team, and a great player himself. However, having a great player helps the team a lot, as was the case with Sanath, Akram and Lara. It still depends on form- if he's in form, the team plays well.
Ganguly- He is described as an aggressive leader, who defends his players, and sticks to his decisions. However, if the team lacks great players, it backfires once too often. He does not adjust to changing situations, even when the pitches don't suit his team and his players don't perform. He is not the best strategist either, and very predictable. That is why the Indian team under him has not won too many tounraments. For FOUR years.
Dravid- many mistake him for being too soft, and not aggressive enough, but that is just an image. He is a very clever captain, which not too many notice. In a match where there were few overs left, and quick runs were needed, Dravid sat out and promoted the fast-scoring Yuvraj and Agarkar ahgead of himself, and it worked. He brought on spinners a lot earlier in ODI's and the ball got a little too slow for the openers. His innovative, out-of-the-box thinking is his main strength. As for his batting form, he is a world-clas player, and one of the best batsmen of this era, and this should not affect his batting. After all, it is a matter of just a few matches. Comlpaints were made about Vaughan's captaincy and its effect on his batting, and he silenced his critics this year. Dravid is a far better player than Vaughan.
Laxman- He has the best cricketing intelligence and sticks to what's best for that situation, in the match. Reputed journalists and experts tip him as a future captain, because of this. He has done well as a captain of his state side, so he has experience. There may be some asking if he is a certainty in the side- he is a better player than the Indian team's regular captain.
Kumble- The Indian team, as a bowling unit, will benefit. He sets attacking fields, and does not give away easy runs. A hard trier on the field, he can be effective as a captain, when given a chance. He should not be branded 'less than a certainty'- he is the team's strike bowler.
Sehwag- An aggressive player will make a good captain, but only when in form. He too think out of the box, and the character that he is, he does not mind taking the attack to the opposition. He has not been given many chances at captaining the Indian side, and must turn out for the rest of the domestic season as Delhi's captain..
Kaif, Harbhajan- These two are not certainties, and are too hot-tempered.
Pathan, Karthik- These are rank outsiders.