Well, the N4 has only a few months on the market and there's already rumors everywhere about the next Nexus device. A lot of people consider Motorola to be the next Nexus manufacturer.
I open this thread to see any news about this kind of rumors, let me start with the first one:
LG Nexus 5 and Nexus 7.7 rumors commence: higher-resolution screens, Google I/O announcement
According to this article, Koreans say that the next Nexus (most likely the Nexus 5) will be made again by LG (!?!?). It will have a 5.0" display with full HD quality, a Tegra 4 processor and will keep the "budget phone" category starting al $299 the 8 gb version.