The rumors were true - the Ricoh GR IV camera development is now officially announced with:
- newly designed lens
- new image sensor
- new imaging engine
A new HDF (Highlight Diffusion Filter) model is also under development.
The Ricoh GR III will be discontinued in July (already not available in the US for months). The production of the Ricoh GR IIIx will continue for the time being.
The full Ricoh GR IV camera specifications and the press release can be found here:
Comparing the new Ricoh GR IV camera with the existing Ricoh GR III
Via PentaxRumors