Cinemas like to use their auditoriums for coporpate events, sell advertising to local vendors, etc... Additionally, some smaller distibutors may opt to forego the hassle and cost of creating DCP compliant packages if what Red Ray PRO provides is a sufficient equivilence of functionality (i.e. color space, XML playlist/asset functionality, etc...) at a fraction of the equipment/autohring cost... especially if the vastly lower bitrates allow for ease of distribution not possible with DCP.
Hence why I said that there are a number of uses other than motion pictures distributed by major distributors. However, I would also point out that live events are one of the main secondary uses of theaters - the Metropolitan Opera, sports events, corporate teleconferences, etc., as well as "pre-show" material. The likelihood of any of these things requiring or even being available in anything other than HD video is rather small, at least for the next few years. That's why just about every auditorium already has an HD projector that they use now for this purpose. The main use of the Red server that I can see would be for private, one-off rental screenings by indies, where security isn't an issue and it's something many theaters will currently do already. If the box is cheap enough, it could find placement in those venues.
But I think Mark really meant what I responded to in the first post...