I'm not as knowledgeable as some of the other members on this board but from what I can tell this is whats different between the two cameras.
1. The canon is a 3.5mm microphone jack and the Panasonic is XLR compatible for bigger and badder (professional) microphones.
2. The big difference is the Panasonic is a 3CCD camera and the Canon is CMOS. In short, the Panasonic will get you better picture quality.
3. The canon has a few manual controls it looks like it has focus and exposure controls according to the amazon product description. The Panasonic has manual apeture, iris, zoom, focus and gain functions. The HVX200A also has interchangeable lenses and more "pro" functions.
There are many more things that set these cameras apart from each other, but these are just a few things I've gathered by looking at both of the amazon pages. I have not had any experience with either of these cameras but I have had experience with the HV30 which seems to be similar to the Canon HF100 except the HF100 lacks a manual focus wheel.