See this chart I made for "matters in DVD battles" blow.

However, the most important thing to watch out is the China’s movement. China is probably going to develop better DVD format with lower price and more spec. Even though they don't have any supporters right now, I believe many things will be changed with China's new format. Let us take a careful look for another DVD war.
Those technologies are young and immature, and have room to improve so we have got to watch and wait for their competition with market dynamics. For the argument of Blu-ray and HD-DVD debate, see this blog. I'll keep spy on the China's wind.