Canon launched their "spring" 2011 rebates and put three lenses on rebates.
70-300 - $150 rebate
55-250 - $100 rebate
75-300 - $50 rebate
See Link: http://www.canonpricewatch.com/
for the details.
As they mention, the dreaded Canon rebate rules will force retailers to
price at least at a certain level, but as in the past there are
opportunities for deals in the first day or two when inevitably one retailer
will apply the full rebate amount in error.