The Nikon AF-S Nikkor 16-35mm f/4G ED VR zoom is Nikon’s answer (after many years) to Canon’s EF 17-40mm f/4L zoom. But I suspect that the Nikon offering will yield superior performance, though that remains to be seen, especially at the 16mm end. See my Feb 9 notes for more.
Update: the 16-35mm f/4G ED VR is now IN STOCK .
B&H Photo is now listing the 16-35mm f/4G ED VR as available for pre-order , which means they expect a shipment very soon (B&H won’t sell what they cannot deliver in a short time frame). I expect they’ll sell out quickly, so pre-ordering is a smart move if you’re looking to get one. I’ll be reviewing it soon for DAP.