When they have bandwidth and a deal in place with Turner. Or other owners of other channels.

Although people suspect they will temporarily put some national HD channels on these first two satellites that just went up, they are really for locals only and there is no proof they will ever have a single national channel. They are spot beam sats. The 3rd and 4th sats will be going up in the next 2 years, and these are the ones designated for CONUS transmission.