With a similar performance as the f/1.4 versions, the new AF-S Nikkor 24mm f/1.8G Lens will be much cheaper than 24mm f/1.4 lens.
The f/1.8 lenses have been a huge success for Nikon and it is not a surprise if they decided to expand their current f/1.8 line (20mm, 28mm, 35mm, 50mm, 85mm).
Nikon currently has four 24mm lenses: Nikkor AF-S 24mm f/1.4G ED, Nikkor AF 24mm f/2.8D, Nikkor AIS 24mm f/2.8 and Nikkor PC-E 24mm f/3.5D ED.
And the Sigma 24mm f/1.4 Art lens is rumored to be announced in early 2015.
Read More: Nikon Rumors