Earlier this summer Andy Lau was cast in Iron Man 3 as a scientist who helps out Tony Stark. Unfortunately he had to drop out and in a recent report from Chinesefilms.cn he has been replaced by actor Wang Xueqi. It also looks like there's more to the character he plays then we previously thought.
We've learned that the name of the character is Chen Lu, China's foremost researcher in nuclear radiation and its effect on humans. He's also known as Radioactive Man, and has worked for the Mandarin several times in the comics. So, I think it's safe to say that we'll be seeing Radioactive Man in the movie! Not sure how much help he'll be to Stark if he's working for the villain.
The movie is being directed by Shane Black, and Xueqi joins Robert Downey Jr., Gwyneth Paltrow, Don Cheadle, Jon Favreau, Ben Kingsley, Guy Pearce, James Badge Dale, Ashley Hamilton and Rebecca Hall. The movie is scheduled to be released on May 3rd, 2013.
Here's some more information on the character:
Chen Lu holds a Ph. D. in nuclear physics, and was a normal human until exposed to excessive amounts of radiation, which changed his skin coloring to an iridescent green, and allows him to manipulate radiation across the microwave spectrum. Abilities include radiation emission as heat, "hard" radiation (inflicting opponents with nausea, dizziness, and radiation poisoning), and hypnotic light. He can also absorb nuclear radiation without harm and convert it to energy for personal use such as strength enhancement or to cauterize wounds, create force fields, and emit electromagnetic radiation to deactivate machinery. As the character constantly emits radiation, he has limited human contact and wears a full radiation suit when in the presence of unshielded persons. As a member of the Thunderbolts, Chen comments multiple times how he is not radioactive and the suit serves no purpose. Norman Osborn requires Chen to wear the suit to reassure the public that he is safe and to disguise the fact that he is a foreigner.