I work for the USPS.  Yesterday we received word there would be no live
animal shipments including bees by air.  Thinking this might be the
usual confusion of packages vs. queens, I e-mailed our district HQ.
They called back immediately.

 From the USPS, this is the story:  Due to the 9/11 mess, airlines will
not carry any live animals including queens until further notice.  USPS
will accept bees under usual rules (see previous post) for ground
transportation only, up to zone 4 (the zone may vary by district).  We
(USPS) recently began to contract with FEDEX (not UPS) for air transport
but they do not accept live critters.  This situation may change (I
hope, was planning to order SMR queens now that we had rain) -- it's up
to the airlines, who have bigger problems right now.  Support your local
bee breeder!