I have a JVC MVC file and MyDVD doesn't have an option for this type. MyDVD will import, but the video image is squished regardless of which 3D option I choose. These files are not side by side, half-width , etc. It's a fairly new format. Although Creator NXT Pro just came out, not much has changed in the Video applications from the previous version.
The MVC was designed so 2D editors can still open one stream to edit as a 2D project. Previous format didn't. From what I have read, MVC is now part of the Bluray 3D standard.
Videowave and MyDVD will open the MVC I have as a 2D video just fine, but not as 3D.