Canon Europe has announced that the previously revealed new versions of the company's 300mm and 400mm f/2.8 supertelephoto lenses are now shipping. The EF 300mm f/2.8L IS II USM and the EF 400mm f/2.8L IS II USM, which are lighter than their predecessors and have all new optical designs, have been released to selected professional dealers in Europe. 

There is no official update about availability in North America, but in a previously released shipping schedule, the lenses were slated to begin shipping in the U.S. at the same time as Europe. 

Update 9/2/2011, 12:00 EST:

Canon U.S.A. has informed us that both lenses are also now shipping in the U.S.