It it worth loosing 35mm in zoom?

I'm not sure why I'd want to choose the newly announced Canon EF 24-70 f4L IS over my current "go to" lens, the EF 24-105 f4L IS? Hmm, I was really hoping for a f2.8L 24-70 with IS.

New Canon EF 24-70 f/4L IS & EF 35 f/2 IS Announced « HD Cam Team

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Official Press Release Canon U.S.A. "Widens" Its Offerings And "Zooms In" On Creative Optics With The Introduction Of Two New