At least, I am told the movie was in 3D--it certainly cost the extra two dollars and I did wear my lovely 3D glasses to watch it. But the effect was a little disappointing; 3D done well can just add so much to a movie. The Voyage of the Dawn Treader was probably one of the first times I realized this (even though, of course, that movie wasn't initially filmed for 3D--they just had a lot of postproduction time to work on it), and the 3D of Deathly Hallows last summer was rather amazing at times.
I can't speak for the technical side: I don't know what differences there are in making a movie 3D that is twelve years old versus one made today. I imagine that this allows you to do less . . . at least I hope this was the case because Star Wars did not have the best 3D moments. Some were good, and I do believe there was an overall added clarity, but mostly I was just excited to see this movie in theatres for the first time. As I mentioned when I talked about Beauty and the Beast in 3D, it's different seeing a movie on the big screen instead of on a VHS at home.
As I think we all know, there were some minor adjustments to the film itself. Most of them were small, fairly inconsequential things. There were nice added shots of the cities (similar to the adjustments made on the original trilogy) that I certainly wouldn't want to complain about. The odd thing was the addition to the pod race, the scene already infamous for being long. Okay, the bits added were interesting to see--they showed how Anakin managed to win the race, but I don't know if they were completely necessary . . . I guess it doesn't matter, anyway.
Still, I have a weakness for Star Wars, and even if I consider myself primarily a fan of the original trilogy, I'm not so against the prequel trilogy as, er, most people are. I was glad for the chance to see this movie in a theatre, even if the 3D element was very little to boast of (let's hope it will be better next time), and I will certainly look forward to watching the next five movies likewise in the years to come.