If you wanted to create a Blu-ray disk of a TV series, for example, that was recorded in MC using the JTV format, you would have to:
1. Convert the JTV files to some other format
using MC, since it is the only software that I know of which can convert the format.
No longer true. Have a read of this thread: http://yabb.jriver.com/interact/index.php/topic,105793.0.html and maybe this one: http://yabb.jriver.com/interact/index.php/topic,92571.msg744310.html#msg744310 When you do this, be aware that you will only get stereo audio out, as the conversion functionality does not retain any multi-channel audio broadcast and recorded in AAC or AC-3 format.
2. You will probably want to trim the start an finish of the TV show to get rid of the padding from the recording, and maybe to trim out commercials. You will need a third party tool to do that. VideoReDo is a good tool for this job, but check which formats it supports first, and use the trial to check how well it works for you.
3. Create a Blu-ray disk, and burn it to optical media. You will need a third party tool for this.
I doubt very much that MC will ever support Blu-ray disc burning, or creation of the Blu-ray structure.