The high-bandwidth FTL communications link isn't looking too likely under the laws of physics as currently understood. The holographic telepresence setup, however, is almost technologically feasible - if not currently buildable for less than an arm and a leg. The network-ready video cameras exist (although they're not holographic); the body-sensing gear to know where the user is looking exists; and there are even a number of different ideas floating around for generating images in empty air. But no one has surmounted the technological challenges inherent in putting them all together in a package which the discerning mad scientist can afford on a budget.

I remember seeing something like a "holographic telepresence apparatus" when I went to SIGGRAPH waaaaaaay back in 1993. I was wearing an onion on my belt, which was the style at the time, when I happened upon a huge booth in the exhibit hall. There was a wall about ten feet high and ten feet wide covered in chroma-key material, and a giant rear-projection screen mounted ninety degrees from it, and a TV camera pointed at the chroma-key wall and about fifty grand worth of Silicon Graphics hardware between the camera and the screen. The SGI could isolate your image in front of the chroma-key wall, add 3D "objects", and render the result on the rear-projection screen so you could interact with them in real time.