Wow - that really is conflicting and misleading information. Cognos 8 does not interrogate the OS to determine how many CPUs/cores are available, and cannot automatically modify the number of report processes to suit. Either the message at Forum 2009 was misunderstood, or the presenter was mistaken.
Maybe he was referring to the maximum number of concurrent reports which can be run, which is the number of defined low affinity connections multiplied by the number of defined report services? Still, both of these do need to be set manually by the administrator, so I have absolutely no idea where the concept of auto-detection came from.
Hope that helps!
MF.