In my opinion
1. Satellite (carrier) costs are huge and recurring every year based on the number of TPs rented. For any business, using single satellite makes more sense than worrying about re-alignment of dish. Cost per transponder leasing is around Rs.20 Cr. to 25 Cr per year.
2. Rs.200 to Rs. 250 per dish realignment will be the cost (in bulk). Hence spending that amount will be cheaper than satellite renting charges (About Rs. 50 Cr one time charge considering 2 million customers)
3. They will do it in a phased manner across India
4. To gain more business and customers, they will combine all the available channels from D2h and DishTV
5. ST2 has 41 Ku band transponders. How many are free as of now is not clear. However, based on the demand they can realign the free antenna's on the satellite to beam signals to India, if all the 41 are not being used. This will add capacity to the ST2 satellite
6. As long as the STBs support the encryption formats. it doesn't matter using the same box in different satellites. After encryption issues are resolved (which is already done by adding Conax by D2h), it is only matter of SW updates to the box.
7. NSS6 was launched in 2002 and it makes sense to consider ST2 which was launched in 2011 for an uninterrupted service. (may be moot point. there will be plan to have a new satellite at 95 deg, E.)
Whatever it is, I feel it's going to benefit customers. Price war may continue if Big TV manages to deliver what they promised. Also, more people are hooked on to mobile videos than watching the usual TV. But one TV per home is going to continue.