Frankly, the technology as well as the price has quite a way to go yet before it becomes standard practice to use such things. Not every player will want to be (or can be) at the same distance from the screen, depending on the instrument that he/she plays, and the screen resolution will need to be very high to make this work effectively at any reasonable playing distance. The computer glitch and power-out problems are also valid issues, of course, although the latter can at least be overcome in public performance situations by the use of an emergency generator which will also power up the lights and all other electrical requirements in the event of an outage.
One advantage of this technology (once it's mor affordable and of better quality) will be the lack of any further requirement for a page turner, since a pedal could be used for this purpose; this would only be a problem for organists and pianists (and to a lesser extent orchestral harpists) who already have pedals on their instruments, but the organist could devolve the job to his/her assistant who will already be dealing with registration issues and the harpist won't find it an issue except where a screen change coincides with instrument pedal changes. The pianist might be able to overcome it by means of something equivalent to a thumb piston attached in front of the keyboard, such as an organist operates, although this will add another minor technical factor to playing issues. It will be great for orchestral string secions in that second players on each desk will no longer have to turn pages while the first player continues to play.
Until and unless this technology becomes cheap as chips (and, let's face it, prices of such items plummet only when there is mass market demand, which is unlikely to befall this), there will be the added problem of security risk (theft, etc).
Best,
Alistair