MASN is not the best deal by far for the Nationals but make no mistake, it was put together by MLB as part of the compensation deal to Angelos and IT IS NOT GOING AWAY.
Yes for the next three years Angelos will have to pay the Nats at least $20 million dollars a year for their local TV rights. Then the MLB TV committee will review the the top ten rights fee's. Since the Nats are in the Washington, DC TV market they are in the Top Ten and so it is very likely that the ammount will go up to around $25 million.
Don't forget next season both the O's and the Nats will be on MASN and this is a 20 year deal.
The new owner of the Nats will take the MLB stake in MASN and in time that will be worth up tp 33% of the network. However, unlike the O's money, the NATS MUST MAKE NO LESS than the 9th best LOCAL TV DEAL for the 20 years of the agreement.
Best we call the Dish and Cable companies because like it or not MASN is here to stay. Maybe down the liune we will see a deal between MASN AND COMCAST SPORTSNET, but that could be at least a year away, and most likey much longer.