Asobinet posted this accurate size comparison between the new Sigma 24-70mm FE, Sony 24-70mm f/2.8 GM and Tamron 28-75mm f/2.8 FE zoom lenses. We finally have some nice choices :)
Sigma 24-70mm FE lens at Amazon, BHphoto, Adorama, Calumet DE, FocusCamera. WexUK
Sony 24-70mm GM lens is at Amazon, BHphoto, Adorama.
Tamron 28-75mm lens at at Amazon, Bhphoto, FocusCamera, Adorama, Amazon DE, Amazon UK, Amazon FR.