B&H has deals on Canon Speedlites with up to $60 instant savings. However, the 600EX-RT is $449 in the shopping cart (reg. $549). All are available with free shipping and 2% rewards. Check them out here at B&H Photo.
Canon has kicked off another lens rebate program for fall 2013 comprised of over 40 lenses, along with several Speedlites. The deals include both mail-in and instant rebates. Check them all our here at B&H Photo.