Not to rain on some people's parade here but:
There are lots of other launch facilities that are not 'booked up' if they had a ground spare, they could get it up if they wanted. (Wallops Island Va is just one)
Open your umbrella.
Wallops Island has 2 problems:
1. They are limited in the size of launcher they can handle right now.
2. They are located further from the equator than say, Cape Canaveral.
Payloads are built for certain launchers that are meant for certain locations. The closer you are to the equator, the greater mass a launcher can lift into orbit. Simple physics.
Plus, a satellite doesn't just fit onto any launcher. There are mating concerns. ILS has done work on making the connection as common as possible for their Proton and Atlas launchers. But you don't just take a payload off a Proton and slap it onto a Sea Launch, for example. The physical and electrical connections are different. Plus, the vibrations, G forces and other conditions experienced during launch vary from launcher to launcher, making some launchers unsuitable for some satellites. To beat that to death, a human rated launcher has far greater reliability and redundancy but also, generally, less vibration and sometimes lower G forces.
It doesn't matter if Wallops is available, anyway. The constraints aren't usually regarding the availability of a launch site. It's the availability of the launcher itself. These rockets aren't just kept on the shelf, they're built to order. The only exception to this that I know of, for commercial satellite launches, where rockets were built on an assembly line and actually warehoused, was - ta da - the
Proton. And even they don't do that any more. Matter of economics.
Yep, I agree. Of course Dish/Echostar/SES/ILS etc all have plan B, and C and every foreseeable contingency has been considered. It is amusing that some people post that these massive corporations are winging it. And they're certainly not going to help their competition by revealing their plans any earlier than they have to.