As previously mentioned
Ricoh is working on a way to read all four formats with a single adjustable laser, and they came to Interopto 2006 to show it off. Of course with their panels written in Japanese it's a little hard to understand the details, but the idea is clear. They claim they will be able to provide samples to OEMs this year, but don't anticipate players on shelves until the end of 2007. Of course some people think the Blu-ray and HD DVD format war could be over by then, and we still have the unknowns of license restrictions and price to deal with before this is a realistic alternative to existing standalone players and recorders.