From what I read, it looks like they had only used one projector in concert, which probably limited the viewing angle ... Also, correct me if I'm wrong..., somebody said it only costed Dr Dre half a million? which I imagine is why the hologram is also somewhat transparent (around 3+ minutes into it), and not completely clear

Imagine if millions were spent, and spent more time rendering the image(s), and have more than one projectors, so that it's in full 3D
Damn, that'd be intense.

Like I said earlier, I hope to live long enough for a "Holodeck" gaming experience. In Mutiplayer, we can literally blast each other! or, actually, our Avatars!

EDIT: Aww, I'm disappointed. The technology isn't even remotely close to holographic projections (Holodeck) as I thought it was

yuuup. However, I'm more interested in the ... uh... more sensual experiences. 

LOL! yeah, that coupled with infrared for a complete interactive experience

Japan have been doing similar concerts like this for a while now haven't they? Probably just me but I find it a little unsettling, especially if I saw a Freddie Mercury hologram at some form of fan performed Queen concert.

   Actually it was not a real hologram, just a 3D model of Tupac made by Digital Domain projected on a glass panel in a classical optical illusion technique called Peper's ghost. I think Hatsune Miku and X Japan's hide in Art of Life were real holograms(hide footage taken from old Art of Life concert).

   I think they are walking on a very thin line here. While it's ok to make this a one time only thing as a tribute to dead legend, making regular concerts and tours with dead people's holograms is very unethical and disgusting even. It's just milking money from the fame of a dead person. I understand that show business was making this for decades(if not centuries) with selling after death albums and merchandise, but showing hologram mimicking dead person for entertainment of a crowd is taking it too far IMO.

That alone makes me sad! Tupac the G.O.A.T.

They would have gotten away with it, too.  If it wasn't for that meddling Lazlo23!