Upload & Sell: Off
I'm more curious why the Canadian prices aren't dropping.
eg. 135L f/2 $900 US, $1240 Canadian. Current conversion rates should give a US price of $1200. $300 difference!
Canon Canada has traditionally been slow to respond to price changes in the US market. For low volume items like a 135L it probably doesn't really matter to them, but for something like DRebel kits, or even the 5DII, there is more incentive to keep prices competitive. While I haven't checked, I suspect they're fairly close.
As for why we're seeing the US price drops... I'll echo a couple other posts and peg it on Canon USA trying to hit end of year targets. Every large company sets yearly sales goals and it's possible that Canon USA is coming up a bit short. So, with the Christmas shopping period falling conveniently at the end of the year, dropping prices on select items is a good way to encourage fence sitters to commit.
Edit: Chumma beat me to it with some actual numbers - cool.
A few weeks ago, had I seen the S95 price for $230, I would have bought one for sure...