I have a real cheap DVD player (40.00) that does not claim to be able to read any of these formats but, as an experiment, I burned a DVD and tried it (with success). What I did do was use Ulead Visual studio and created a DVD video format (which ir was only able to do on -R).
The dual layer is an upcoming option to squeeze more onto a DVD. This is already used on commercial DVD's but that is a side issue.
I know this is not a complete reply but it might help.