I have the same problem...
Express Mail International®   Processed 
Through Sort Facility - November 24, 2012, 10:39 pm
                                       ISC SAN FRANCISCO (USPS) 
                                    
                                           Electronic Shipping Info Received - November 25, 2012
                                       
                                           Arrived at Sort Facility November 24, 2012, 10:37 pm
                                       ISC SAN FRANCISCO (USPS) 
                                 
                                           Depart USPS Sort Facility - November 24, 2012
                                       SEATTLE, WA 98168 
 
                                          Processed through USPS Sort Facility - November 23, 2012, 9:48 pm
                                      SEATTLE, WA 98168 
    
                                     Acceptance - November 23, 2012, 5:04 pm
                                     MONROE, WA 98272 
    
I assume it is in customs because this is what the Canada Post tracking shows me:
2012/11/24    22:39    USSFOA,USA    International item has left the origin country and is en route to Canada        
                    22:37    USSFOA,USA    International item processed in origin country        
2012/11/23    17:04    98272,USA    International item mailed in origin country
5th day now since any updates and 6 days since sent out, but I also have a order from Quebec and it hasn't updated since Monday the 26th... annoying but I am hoping CP is just getting lazy on updating the tracking. I just keep telling myself "it is not a postal strike, it will be here soon, it's not a postal strike".... and then I dance around the mail box naked while continuing the chant! 
Edit: Cyber Monday shipments are probably to blame as well. I really don't understand the update on Nov 25th (Electric Shipping Info received). It is actually in between the two updates on the 24th?