→ It does exists: Nikon lens pillow.
→ New: Really Right Stuff plate for Nikon Df camera.
→ Tokina AT-X M100 AF Pro D 100mm f/2.8 lens for Nikon mount ($449) tested at DxOmark:
“Although Tokina hasn’t updated this lens since it was introduced in 2006, it still has very competitive performance, and when stopped down is even sharper than the $899 Micro Nikkor. While the Sigma 105mm f2.8 has comparable sharpness at any given aperture setting and boast ultrasonic focusing and stabilization, like the Micro Nikkor, it’s still $220 more expensive than the Tokina and neither have the aperture collar that’s coveted by serious macro photographers.”
→ Updated support document: WU-1a ($54) and WU-1b ($54) wireless adapters compatibility with Nikon cameras.
→ Interview with the Nikon Df design team (Google translation). Here are some key points: