I brought up the difference in technology issue on another board, and was roundly criticized to "get over it" and quit obsessing about it because it's 2012 and you can't have CRT monitors in a science fiction film set in the future anymore.
My feeling is that this is a bullshit excuse. The excuse actually bothers me more than the fact of the tech discrepancy itself.
It's an alternate reality, not our future (just look at the timeline on weylandindustries.com if you think this is supposed to be our future), so who's to say what technology is "supposed to" look like in this alternate future? Is Alien automatically unwatchable because the technology on the Nostromo is not flashy enough? Maybe to some, but not to me. What it does do, is hurt the continuity. It makes it harder for me to suspend my disbelief and buy into Prometheus as a true prequel to the Alien saga, as opposed to a J.J. Abrams-style reboot.
The flashy CG floating see-through displays seem like pandering to Avatar-fans, not like the meticulous, thoughtfully considered aesthetic of a director like Ridley Scott. I'll still see the movie, and let it stand or fall on the merits of its story/acting/directing, but it's just disappointing to me. If any director could've made "antiquated" technology look sexy in a 2012 film, it's Ridley Scott. Hey, Duncan Jones' Moon succeeded wonderfully without needing to wow the kids with fancy holo-displays. That film's aesthetic would fit right in with any number of classic science fiction films of the 20th century. Ron Moore's Battlestar Galactica series made nice use of more traditional set design also.
Like I said, it's not a deal-breaker, it's just disappointing. Seems like the path of least resistance to me, like it's trying to appeal to teenagers more than to fans of the original films. As others have duly noted: the exact same problem a lot of us have with the SW prequels.