I think its too early for NDTV to sign Dhoni. He is yet to make his mark. Though he topped the list of ICC we will have to see his consistency. Otherwise he will turn out to be just another Sehwag !
I think NDTV by contracting Dhoni for their commercial purpose will detroy the roaring of the lion or it will atleast disturb his mind from playing to commercial line and history will be repeated