If you can have SACD/DVD-A players - no reason not to have hd dvd/bd players.
There were 3 announcements about universal players that were quickly withdrawn - by Samsung, LG and Pioneer (actually a drive announcement). So it is possible there are contractual agreements in place to prevent it for the time being (probably 2006 ?).
The big step in universal players is not the SOC - already the toshiba HD DVD player and the Samsung BD player use the same chip. What is critical is the drive (in particular the OPU).