issoisso has the right idea on this one: the pros themselves don't see it as cheating but as the price of being competitive. The lying to the public bit -I'm pure as the driven snow and just a humble workaholic - is part of the script.
The most underwhelming aspect of today's P-R was that only two riders thought they could win. Boonen is great to watch but he did too much work today and lost the race on pure hubris. When Cancellara attacked, no one tried to chase: they all looked to Boonen who was having a drink and a snack at the back. Hushovd, Flecha, Hincapie, Pozzatto et al were all failures and racing for second place right from the start.
As for Cancellara, well, it was a pretty sneaky move to attack when his only competition was refueling. A real sucker-punch of a move. His win is diminished because of this. He's not as sporting as Boonen who was seen to be congratulating Cancellara during the race when the latter chased down one of his attacks from the front.
In the real politik world of professional sport, Cancellara's tactic is perhaps not so taboo where whatever it takes to win is permitted. He may even garner a few extra fans who like that type of thing. Boonen is bound to receive criticism too for what could only be called overconfidence and inattentiveness (but where the hell was his team?)
For mine, however, a sporting champion isn't complete unless they're a decent guy as well. Cancellara doesn't fare well in this regard. He pontificates on other riders (re Cadel Evans Tour 09) and comes across as priggish. For a guy with legs as good as his, he'd do better to let them speak instead.