digitalrev have put up a good review of the 8-15 fisheye http://www.youtube.com/watch?v=IabjY5AmWOk
I think you mean they posted a hey-we're-trying-to-be-the-Top-Gear-of-cameras-by-playing-about-with-new-gear video.
i just purchased a 24-70 f2.8 new on A SPECIAL DEAL with £100 off did i make a mistake?
Only if:
a) You will be forced to live under a bridge because you bought the lens rather than paying the rent or mortgage.
b) The lens, aware of these rumors, decides to do itself in, leaving shards of glass embedded in your body.
c) You're more worried about having the latest and greatest, rather than having solid tools.

Really, it's a great lens, capable of great results. It's a matter of whether you're more into carts or horses and how that directs your choices, to twist a colloquialism.