Nothing major, but it seems IM3 was still filming in Beijing this week. 'Dr. Wu' actor Wang Xuequi was spotted (in a video) in his surgeon uniform. Chinese actress Fan Bingbing, who was said to have a role in the movie months ago, was there also.
I wonder if it has anything to do with the post-credits scene. Anyhow, fast forward to 0:30 mark for the short video. I think someone even has an IM3 jacket on.