Associated Content has put together an interesting article comparing Blu-ray and HD DVD. Instead of examining video quality or disc capacity, they look the two formats from the perspective of a DVD author.
Once again I have to give the nod to Blu-ray Disc. There are basic technology aspects as stated above, but from an authoring standpoint, there are advantages to working with BD over HD DVD. Granted there are not currently a lot of authoring tools available. With the exception of Sonic Solutions, there are not any HD DVD/BD authoring applications on the market as of July 2006. That's bound to change in the next 6-12 months, but for now, most HD DVD and BD titles are being hand jammed, a process more akin to software development than DVD authoring. When fully implemented authoring programs do become available, it will soon become clear why BD is better.
This is definitely an interesting read. If you'd like to check it out, the entire article can be found here.