based on the photo -
i would say - FAKE.
the USM lettering on the front is not inline with the barrel and some other letters of the lens.
however, if this is true, i will pre-order right now.
I once own the 135L and 50L and bartered it with a TS-E 90 and 100L macro - which I would say - my friend got the better deal.
So, this one would be very sweet indeed if true. f/1.8 and IS ; AWESOME!