The new Voigtlander APO-SKOPAR 90mm f/2.8 SL II S lens for Nikon F-mount is currently in stock at B&H Photo and Amazon (additional information on the lens can be found here):
The other two Voigtlander lenses for Nikon F-mount are currently on sale ($70 off):
The remaining Voigtlander lens rebates can be found here: