B&H just started accepting Canon EF 24-70mm f/2.8 L II USM Lens preorders.
The expected availability listed for the 24-70 II is April 17 2012. The two new primes are on B&H's site and expected on June 17 2012, but these are not yet available for preorder:
Canon EF 24mm f/2.8 IS USM Lens at B&H
Canon EF 28mm f/2.8 IS USM Lens at B&H