There's no reason why it can't happen. I just don't personally know much about how pdaxrom works.
Right now, we need to run in high def modes, though I am pushing for 480i support. The main thing blocker for that at the moment is just not having a 480i version of the main theme.. and at that size, it's not a matter of scaling down the HD versions... it's really redoing it so that people on 480i can get the best experience they can. But on the technical side of things, almost everything's already in place to support SDTVs.