I'm going with champion on this one and I am unrelentingly pessimistic regarding the amount of doping in cycling. For a number of reasons.
1) Liquigas (and all the rest) who were at the Giro and in the midsts of their own doping scandals. Ok, some riders were withdrawn but the scandals implicated whole teams, for me. So he beat riders who were more than likely juiced up as well. I see this as a sort of 'Armstrong Defence' - I have no doubt Armstrong was juiced up, but so was everyone else so it was in essence a level playing field and Armstrong's dedication won him his tours.
2) Contador has won every Grand Tour he's entered. Doped or not, that's an incredible achievement.
3) As someone else has said, just because someone's dominant, it doesn't mean they've cheated. Much cited through the ages is the phenomenal win record of Merckx. Who tested positive. I know, I know, there are differences but let's put the rose tinted glasses away for a minute and acknowledge that the legend we love was hated so much that a spectator whacked him in the kidney in '75.
4) Doped or not he's far more exciting to watch than alot of GT winners of late. He attacks. He rides other events,has even won the odd Classic whilst in his Tour winning prime. Just like Lance, oh...And he's not sticking to riding the TdeF when it comes to GTs either. These things have to be good for cycling - a champion riding more than one race and trying to win them rather than using them as training.
5) More of an aspiration this one. Cycling looks pretty stupid and the delay now means that he could potentially have 2 TdeFs, a Giro and a Vuelta (let's speculate he wins the triple). I just don't want the sport to have to take that kind of hit to its credibility. I acknowledge that sounds desperate.
Anyway, my view, who cares about the clenbuterol, I think questions should really be asked about the plasticiser which is evidence of far more dubious practices which are clearly still alive in the sport. Ricci was probably only doing what plenty of others get a doctor to do but because no one would go near him he took the risk of doing it himself.
Purely from a sporting point of view - I think Contador is a champion (but I'm not 'steaking' my house on him being clean).