while Canon is dragging its feet to replace the outdated 100-400/4.5-5.6, Sony goes ahead with a 70-400mm F4-5.6 G SSM II lens announced today.
http://www.dpreview.com/news/2013/02/20/sony-lenses-50mmzeiss-70-400mm
The specs look good http://www.dpreview.com/products/sony/lenses/sony_70-400_4-5p6_gssmii/specification
Only slightly larger and heavier than the Canon 100-400, but faster at the short end - f/4.0. Same 77mm filter diameter. Rotary zoom design.
Canon ... WAKEUP CALL!
http://www.dpreview.com/news/2013/02/20/sony-lenses-50mmzeiss-70-400mm
The specs look good http://www.dpreview.com/products/sony/lenses/sony_70-400_4-5p6_gssmii/specification
Only slightly larger and heavier than the Canon 100-400, but faster at the short end - f/4.0. Same 77mm filter diameter. Rotary zoom design.
Canon ... WAKEUP CALL!