Anti-aliasing filters are the new, uh, thing that’s not popular any more. Ever since Fujifilm redesigned it’s sensors so that they no longer need a blurry filter in front to smooth out jaggy moiré patterns, everyone has been jumping on the anti-anti-aliasing wagon (not to be confused with the AA wagon, which is where inveterate boozers go to reduce their own blur).
The latest of these is Nikon, which has taken the AA filter out of the new D5300.