Canon EF 70-200 F/4 IS L hits the market

The NEW Canon EF 70-200 F/4 IS L announced at photokina and armed with the latest generation of Canon IS that can achieve 4 stop Image Stabilization finally hits the market with a street price of $1249 USD.

BHPhotovideo and adorama are already accepting pre-oders for the canon ef 70-200 f/4 L IS
17Photo will ship it in 3-5 days.
It seems that the winner is adraycamera that claims to have the lens already in stock.

The question remains, for a price difference of only $450 with its biggest sister the Canon EF 70-200 f/2.8 L IS and shipping without tripod collar (dropping the difference to just $350) and if you buy the f/2.8 during the canon fall double rebates you can have an extra $100 money saving.
Who would go for the Canon EF 70-200 f/4 L IS for just $250 savings?