Training in professional cycling has improved and become more sophisticated and systematic in the last 20 years, to the point that top cyclists train to "peak" at a specific time of the year (like other sports like track and swimming). For example, Pantani was the last cyclist to win both Giro and the Tour de France, and one may wonder as well just how much chemical help he was getting that season... In fact, the commentators on Versus for the Criterium International were originally questioning whether Contador might be peaking too early this season... Personally I think Contador is a class above the rest as a climber, which allows him to win Paris-Nice and still likely do much damage in the Tour de France later this year...
For me the most interesting part of watching Paris-Nice and the Criterium International is trying to gauge the level of support Contador can expect from his teammates this season. After the departures of Armstrong, Popovych, Leipheimer, etc., Astana recruited pretty aggressively (Pereiro Sio, Noval, etc.). But Contador's team looked weak during Paris-Nice, and even though it looked like Vino, Fofonov and others were pacing the field at some point in the stage yesterday, the reality is that none of these riders were anywhere to be found at the end of the stage. I also worry about Vinokourov's possibly disruptive attitude within Astana - "his team" as he is fond of reminding everyone... Not that Contador has had to deal with that issue before :-)
To me the strongest team so far this season looks like Caisse d'Epargne... I think Valverde could surprise a lot of people come summer time...