It seems like Nikon is really continuing on with the DX product line-up. they have just announced the new AF-S DX Micro NIKKOR 40mm f/2.8G for cameras ranging from D3100 to D300s which is having DX crop sensors.
Check out the sites below for more details:
- Nikon AF-S DX Micro NIKKOR 40mm f/.8G Announced As New Affordable Macro Lens (slashgear.com)
- Nikon launches AF-S DX Micro Nikkor 40mm F2.8 macro lens (dpreview.com)