True. The reason I asked this was that with Sky and Freeview certified STBs thec ontent providers seem paranoid about allowing you to watch HD content over analog that they specify HDMI only so I suspect the same reasoning would prevail with copying recored HD to Blu-ray but would only allow copying only to DVD format.
If that is the case, then you could only do SD to either DVD or BluRay, in which case the only advantage of a BluRay burner would be more SD content than standard DVD.