The answer is no. Despite that fact that MainConcept does have 64 bit versions of its various codecs (at least they refer to them on their website, but I've never seen them "in the wild"), Adobe decided to stick with the 32 bit codecs. Premiere Pro CS5 uses a surrogate program to communicate with the 32 bit codecs, just like Vegas Pro does.
I'm guessing that the use of the 3rd party 32 bit codecs is associated with licensing issues. SCS and Adobe probably would have to negotiate a new license with MC for embedded use of their 64 bit codecs.
I'm guessing that the use of the 3rd party 32 bit codecs is associated with licensing issues. SCS and Adobe probably would have to negotiate a new license with MC for embedded use of their 64 bit codecs.