I'd like to believe he wasn't, but common sense says he probably was doped.
I'm not sure why people bring up the facts of his cancer, the work he's done on behalf of those with the disease, or (as Armstrong himself sadly does), the supposed animosity between Americans and French. None of those things are relevant since none of them can put EPO in a blood sample.
I believe he's probably guilty of what they're accusing him of because...
He's always been quick to sue in the past. He's backed off on that now. Why? Because he knows that closer examination of the facts can only bury his rep deeper. Armstrong is resting his argument on the fact that these damning tests did not follow testing protocol. So what? Anyone know how many times tests that do follow the protocol disagree with the results of tests like the one Armstrong just failed? Virtually never.
The whole argument about the length of time the samples was frozen is a red herring. Improper freezing might degrade a sample, but it would NEVER put EPO in a sample if it wasn't there in the first place. No one is challenging the presence of EPO in the sample. There's been talk of conspiracy and sample switching, but the majority of that has been innuendo spread by Armstrong himself.
If he did cheat, he deserves to be exposed. He's told fans he "feels sorry for the accusers because they don't dare to dream big", to imagine someone could achieve great things without cheating. If he betrayed ideals that are still important to many, or more to the point only pretended to uphold them, that would be unapardonable, and he'd deserve all the embarrassment and ignomy that could come his way.