I see PCI Express as more of a "stuck with" than a "must have".

No kidding. The real reason for PCIe is to force upgrades.

Just like the real reason for DTV is to sell digital receivers.

And the real reason for HD-DVD is to take another crack at working DRM,
since CSS failed so badly. Improved picture and sound quality are a red
herring, and will only impact a small minority of people who actually
have HDTVs anyway.