Blood doper Vinokourov back in action?

The Astana professional cycling team has certainly been an interesting team this year.  From the reappearance of Armstrong (for me, an unexpected force at the Tour de France), and the subsequent soap opera that ensued as Armstrong and Contador jockeyed for preeminence through the duration of the Tour, to the reassertion of Kazakh control and the departure of Bruyneel, Armstrong et al to form the new Radio Shack team, it's been pretty exciting.

Now, Cyclingnews.com reports (Vinokourov to head to the Tour of Spain with Astana) that Vinokourov is back in the Astana fold after serving his ban for blood doping, and will lead the team at the Vuelta.

But what happened to the rule that doping bans were extended to four years for Pro Tour racing? Am I deluded in remembering that rule, or does/did it actually exist?