You can watch non-HD programming on the HD feed and it WILL look better than the basic channel feed -- there's more information being transmitted for the picture compared to the regular feed. However, the original tape itself is not in high definition. Some other sports on ESPN still aren't in high definition, such as boxing, Champ Car racing, and other niche sports. While ESPN has the HD cameras readily available, there is still a high cost in operating them and providing an actual HD feed, etc. That's why you still see a handful of NFL/MLB/etc. games filmed in standard definition even though most are in HD now.