Does your camera encode your videos in AVCHD? if it does you can create a AVCHD DVD which is basically a Hi-def copy that can play in a blu-ray player (burned on to a normal DVD). although the amount of stuff you can fit onto a DVD is extremely limited compared to a Blu-ray disk you can still surprisingly fit quite a bit of video onto a AVCHD DVD.
About your second question as long as you can rip the HD DVD data you should be able to rencode it using DVDA and VEGAS to blu-ray format.