Canon EF 24-70mm f/4L IS
I have the new Canon 24-70mm f/4L in hand and will be posting some comparisons against the 24-70mm f/2.8L IS II very soon.
The coverage will be grouped with my existing review of the 24-70mm f/2.8L II.
B&H Photo has both the 24-70mm f/2.8L II and 24-70mm f/4L IS in stock.