Scott - They are available. Part numbers are SZ-2, SZ-3, SZ-2TN, SZ-3TN, SZ-2FL and SZ-3FL. I can't tell the difference betwwen the "2" series and the "3" series, except the "3"s seem to have less tinting. Details can be seen near the bottom of the page at WA:Filters" target="_blank" rel="nofollow">http://www.nikonusa.com/Nikon-Products/Photography-Accessories/Speedlight-Flash-Accessories.page?#!/ta WA:Filters and Diffusers
Apparently, the link above is too long to post as a hyperlink. At NikonUSA.com, click on "products", "accessories", then "Speedlight accessories", then go to the bottom of the page.