If you know anything about Tendulkar is - his personal life goal is to win the world cup for India. We know how disappointed he was last time, even while receiving the Man of the Series trophy.
One thing I am sure, if perhaps, Ganguly doesn't pick up form and gets dropped, then the only guy who will rise to challenge of leading the team then could be Tendulkar or Dravid. Tendulkar, given that he has expressed openly that he doesn't want to captain India again, looks like Dravid would end being captain.
So, after looking at the discussion one common theme has been - Either Ganguly or Laxman or both would need to take charge, play responsible innings, to their potential, or should give way for other players.
The perfect composition, as I mentioned before for the team would be
5 specialist batsman, 1 all rounder, 1 wicket keeper batsman, 4 specialist bowlers
For the batsman then, likely players to stick till next world cup -
1) Sehwag and 2) Tendulkar (opening, we all know how destructive these two can be, ask Pakistan from last world cup, particularly Waqar, and Akhtar)
3) Kaif (dependable)
4) Yuvraj (poor in technique, but a hitter and timer and suited for ODI)
5) Dravid (dependable)
That makes my 5 batsman, why would I need a Ganguly or Laxman or Mongia then?
6) I would rather pick an all rounder (can bat and bowl)
7) Wicket keeper (Kartik or Dhoni, whoever picks form in the next 2 years)
8) Pathan
9) Harbhajan
10) Kumble (if he stays fit and in form)
11) Pace bowler (some one who could good company to Pathan, possibly a fast bowler)