I haven't seen this anywhere, but why dosen't a company, or manufacturer just build a Blu-Ray burner without DVD and/or CD support?
This would make the resulting device much less complicated, wouldn't it?
I would be happy to hang on to my current DVD and CD burners, and purchase a Blu-Ray burner that only reads/writes Blu-Ray discs.

This could also be applied to HD DVD burners.

Just my 2¢
Jon