Nikon will announce a new Nikon D5500 DSLR camera in January, 2015. For now I can only confirm that the new model will have an APS-C sensor and touch screen LCD screen. I am not sure why Nikon decided to skip the D5400 iteration. I believe the D5500 is not going to be the only DX DSLR camera that will be released in early 2015 – a D7100 replacement is also expected and it will most likely be called D7200 (no D9300 updates for now).
I think the official Nikon D5500 announcement will be in early January (probably during or shortly after the CES show in Las Vegas), the D7200 could be announced later (maybe for the CP+ show in February in Japan).
Since the Nikon D5200 is already listed as discontinued, expect the prices of the D5200 and D5300 to drop even further in the upcoming weeks before the official announcement.
If anyone has inside information on the upcoming Nikon products, you can contact me anonymously here.
