I just read somewhere that this lens is now discontinued. I was thinking of buying this lens and I know that it's a pretty old lens. Does anyone know about what Canon is planning to do as far as replacing this lens in it's lineup? I know this has been a very popular lens with having the IS and just a stop slower than the f/2.8 version. Oh and about $6000 less than the f/2.8 version. I would be interested in knowing if this lens is going to be replaced with a newer version .