I did get time to go and see Episode I 3D today, and it was a bit of a disappointment (although not really a surprise).
I've never seen any other 3D movie, so have nothing to really compare it to, but the "3D" wasn't visible a lot of the time, and when it was it mostly looked like the bad special FX in an old movie where things look like they've been stuck on top of another layer ... which of course is exactly what has been done since it wasn't actually filmed in 3D in the first place.
I don't think I'll be paying the over-bloated ticket price to see any of the other Star Wars movies in "3D".