I don't know for sure but I suspect that a lot of the push to change encoding from MPEG2 to MPEG4 is that the reduced bandwidth required allows them to use fewer transponders on the birds. As I understand it, solar panels lose efficiency over time and put out less power. Less power means fewer transponders. They can extend the life of the satellite this way. How long will they last? Who knows but I'm guessing maybe another 5 years. If they lose F1R or F2, I'm guessing that they'll just wholesale switch the affected channels to G1 - then we'll not get those channels down south.