Yeah it has 2.5D support for 3D characters. It's still in beta at the minute though, so it's a little buggy & has a way to go before it's completely ironed out.
I don't see any reason why you couldn't import 3D objects as characters. Don't ask me how to do that though mind, as I have no clue about the 3D side of the engine. I will be sticking to the 2D stuff & editor in general. I believe m0fl would be able to answer any questions you have in regards to the 3D stuff.
I think this page here
is the only current page in relation to information about using 3D character models for Visionaire Studio 4.x, at the minute.
I have written up a quick overview of the new outfit properties
tab, in which the 3D settings & options are stored. It can be found here