I believe that B&H posts links to deals on twitter to followers, perhaps facebook as well. I haven't heard of any, but, if Adorama has a 2100 dollar deal, thats very good. I buy from Both companies.
Canon was likely trying to boost sales for 2011, since their bottom line was sufferering due to the earthquake. Prices will go up a bit now that the year has ended, but sellers may still be giving good deals because they stocked up at the low prices Canon offered. After February 4th, they will likely rise again.