... they've done it a few times before, and it IS for a reason, like the earthquake. Supply and demand, no secrets there. That's one of the reasons to increase prices, too - natural disaster; supply and demand. The same thing is happening with prices of hard drives due to flood in Thailand.
It's much better for Canon to say the world economy forces us to up the prices worldwide, than do a halfass attempt to squeeze more money out of customers by slight upgrades, then no one would by them either, and production costs, it just wouldn't make them any money....It won't be "halfass" - you'll get new coating that will reduce light scatter and increase scratch resistance; or in the case of 35L you may get weather sealing, too.
So, what price increase scenario is more likely to be accepted by the public?
1. World economy forces us to up the prices worldwide
2. We are "improving" the current close-to-perfect lens with new coating and/or weather sealing and that's why the price of new lens is higher now.
p.s. You have to look at this from Canon's, as a business, point of view rather than from customer's point of view: how to increase profit with minimal expenses.
First off the 4 L IS isn|t THAT old, and scratch resistance is a big upgrade? I think not, buy a filter, which you needed for it to be fully weathersealed anyway, done.
Second, I mentioned the 35 as much more probable candidate to be upgraded because it lacks behind in every way, comparing, of course, to the 24 1,4 II. So for Canon to upgrade the 35 to match the 24, and yes, also with the weathersealing, less ca, better color contrast and corner performance and the new AF and it would be a solid upgrade, but that's very far from upgrading the 70-200 with new coating.
Canon spend quite a lot of time and money to find out what the customers want, we see that again and again, so looking at it from a customers perspective is also what they do.
Small adjustments , upgrades if you will, is done with camerabodies at entrylevel, and some of the cheapest lenses, but not to L-grade lenses. There isn't a single mkIII lens, which means the ones that are upgraded have been around for along time and needs a SOLID workover.