I'm pretty pissed off, since he's denied it for years and was at one time a respected athlete. He's been lying for his entire professional career. So, what do we all think?
If you cheat, you lie about it, it couldn't be otherwise. Everyone who knew the inner workings of cycling knew he was doing it from way back. "Never failed a test" shouldn't have fooled anyone who dug a little deeper than what the Armstrong PR machine was putting out.
Oprah isn't really known for her hard hitting interview style either, which would be part of the reason he is going to her rather than someone with real teeth. I think her most famous is Cruise jumping on a couch saying he is in love, hardly world shattering. That said I am interested to see if he'll take responsibility for his action.
Oprah got the notoriously reticent David Letterman to talk about some fairly embarrassing personal shortcomings, plus it's not in the best interest of her ratings to soft-ball an interview. OTOH Armstrong is still involved in litigation on some issues so I would guess any admission will be fairly vague.