Various reports say it is
We've heard from a few people that the EF 70-200 f/2.8L is in the process of being discontinued.
A few people have said they have attempted to get broken lenses fixed and have been told by Canon USA that parts for the repair are no longer available and will not be in the future either.
Another report says an EF 70-200 f/2.8L that was in disrepair was replaced with a refurbished EF 70-200 f/2.8L IS II at no extra cost. However, don't go breaking your lenses, as this may have been a one off.
I would imagine the current stock of the lens at retailers will probably be the last of them. I've heard nothing about a replacement for the lens, even though I do think there is a place for Non-IS lenses such as this one.