I wrote about camera and lens prices rising a couple of months ago:
http://www.bobatkins.com/photography/Canon_prices_2009.htmlWhile I'm not sure that the current situation of a number of lenses being out of stock is a sign of an upcoming price increase, I suspect that prices will in fact continue to edge upwards, as they have in fact been doing for a while now.
The out of stock situation could be explained by both dealers minimizing inventory (so they don't have as much money tied up in unsold mechandise) and by Canon cutting back on production in anticipation of reduced demand due to the worldwide economiv problems.