Big 3 should play tests only.
Remember that Tendulkar was our top run scorer in the England ODI series, Ganguly our top ODI scorer in 2007 and Dravid has just come off captaincy, they have played their part in ODIs in the past. If the three would to be dropped, India would go through a transition period which may potentially result in horrendous losses of series and then fickle Indian fans (not calling all Indian fans fickle, but many are) will be calling for their return. Check the ODI averages of those who may replace them, they are not that good nor are even the List A averages at what is a very low level.
Somebody listen to me, they need to be phased out, rest some games, play others whilst playing.