Terrifying. My concern is not for the "respect for the dead" element of some people's equations. I suppose what I find iffy about it is the fact these people are, well, dead. And we know that. But, seeing them alive again and performing, even interacting with the audience perhaps later down the line...could really screw with some more sensitive minds.
I wouldn't be surprised if someone rich enough would someday choose to surround himself with naught but holograms of the deceased he loved and admired, thus making of them some sort of "life." It doesn't hurt anyone, true, but it could be dangerous if he really does lead himself to believe they are there.
So, in short, as a concept, hologram performances sound like a neat thing so long as we remember they are, well, holograms. Not alive after all, and never will be. Easier to forget, especially with the changing nature of our reality. Physical tangibility no longer defines what is "real." Things like the Internet, for example, are physically intangible, and yet real. So, we need to keep ourselves in check, and remember the people behind these holograms were of flesh and blood, and are now dead. And never ever, no matter how much we may wish, will they make an appearance on Earth again.
