We're big fans of both of Nikon's previous "nifty fifties": the 50mm f/1.8 and the 35mm f/1.8 DX. It should come as no surprise, then, that this latest prime lens looks to be just as good as its predecessors. It has a built-in silent wave motor which means that it can be mounted on any digital SLR from Nikon, regardless of whether it has a drive-motor (looking at you, D5100 and D3100).
A prime lens is a fixed-focal length lens, which means that generally they are sharper than zoom lenses, particularly the kit lens that often comes with entry-level SLRs. They also have a wider maximum aperture allowing for increased flexibility in low-light shooting, and creative depth-of-field effects, like achieving that much-desired background blur effect on portraits.
The main difference between this lens and the 35mm f/1.8 DX lens? It all comes down to that DX label. The 35mm is best suited for use on the company's crop-sensor (or DX) cameras such as the D3100, the D5100, the D7000 and the D300s, while the new 50mm f/1.8 is best-suited to full-frame (FX) cameras. That said, as Nikon's lens mount is the same across its range, you can use any lens on any camera; however, the effective focal-length may change. Expect this lens to be available from June 2011 for AU$299.