Forget HD-DVD you can edit your HD video in imovie 08 and then send it to Blu-ray disc via either Toast titanium or you could author one via Adobe encore.
As stated above, Toast 8 does not support authoring BluRay video discs. You can put the HD video files on a BD-R, but it's just a data disc.
Perhaps Toast 9 will include this feature. It's only a few months away.
Don't know if it was mentioned, but DVD Studio Pro supports burning HD-DVD video discs using standard DVD-R (DVD5/DVD9). These discs will hold about an hour of HD video on a DVD-R/SL, and will play on standard HD-DVD players. The only thing is that DVD Studio Pro is $$$$. I was expecting that iDVD'08 would support this, but alas, it does not.
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