It's a movie so they could be remaking it so it isn't so complicated or too ridiculous like nanotech crawling out of his bones through his skin to create an armor. It could also be the SKIN armor. We'll find out in 2 months.
The Mandarins magical rings aren't imbued in IM3. I'm slightly disappointed, but at the same time I understand. They're supposedly doing The Mandarin for IM they same way Nolan did The Joker for Batman. Giving him enough characteristics from the comics so you are aware of who it is, but keeping it more realistic for the audience.
Did anyone think that Iron-Man ever felt realistic?
I mean.. in a sense, he is. He doesn't have any magical properties or super powers, just technology. I'd imagine we will have something like an Iron Man suit in many years to come. There's already functional robots. Japan recently put out one for $1.2M that you can ride around in http://www.youtube.com/watch?v=TztFUjrI2CE