As I write this, the hot new Zeiss 135mm f/2 APO-Sonnar is IN STOCK at B&H.
Bookmark the Zeiss Gear page for in stock status in general; the buttons are updated twice per hour with in stock status, so you can see at a glance what’s in stock or not.
The Zeiss 135mm f/2 APO-Sonnar is the highest performing lens in the entire Zeiss ZF.2 / ZE lens line, indeed one of the highest performing DSLRs lenses available, and is thus a must-have for any serious shooter.
See my in-depth review of the Zeiss 135mm f/2 APO-Sonnar, including coverage and comparison with Nikon and Cano lens, and even performance on the Leica M Typ 240.
Canon users in particular should study the comparison of the Zeiss 135/2 APO-Sonnar to the Canon 135mm f/2L.