Who needs HD-DVD anyway? The technology is still developing, no real reason to need it. Standard DVDs are fine for 99% of consumers. Besides, what if Blu-Ray comes out on top? Personally, I think HD-DVD will...
Making the HD-DVD add on separate was a genius marketing move for Microsoft. Not only does it significantly reduce costs of the regular console, but you can buy a $200 USB HD-DVD add on that's compatible with your PC instead of buying a $500+ HD-DVD drive