Can't be done, mate. HD won't fit on DVD, 720x480 or 740x576 is the best you get. If your mini-DVDs are better than this, they have to be recompressed to DVD specs before authoring.
Maybe when Blue-Ray or HD-DVD drives come out someone will have authoring software for them that can handle this.
Fav quote - "Experience is whatcha don't get 'till ya don't need it no more."
System - Athlon 1.4GHz, Win98, Hauppauge PVR250 receiver and compressor.
Software -Magix Movie Edit Pro 10, Nero 6 + NeroVision Express, Moho 4.61, PSP 8.1, Bryce, Quicktime 6.52 pro, Goldwave 5, DVD-Lab.
Cameras - Panasonic GS9, Canon ES8400V, Canon EOS D20 and Canon A70