According to the rumors the max. diameter will be 108mm, which is too big to fit into most existing ports.
The Nikon 14-24 is 3.8 in diameter, Tom, or 97 mm. SEACAM offers a wide-throat superdome for this lens and Zeiss 15mm at 103mm. The 11-24mm is 109.22, so definitely a bit wider than any lens we've fitted with the wide-throat Superdome so far. We are measured the wide-throat orifice and determined 113mm. Not a lot of room to spare but expect it will be fine.
With the new lens and the new Canon 5Ds in the works, we are very excited to see the US dollar trading so strongly against the Euro, making European housings more competitive in terms of pricing.