Due to differences in electrics, it appears that Intel might have compatibility issues between its upcoming 9-series chipsets and current 'Haswell' processors.
A report from VR-Zone indicates that the upcoming 'Broadwell' CPUs might have problems working on the current 8-series chipsets, as will the 9-chipset have trouble supporting the current 'Haswell' processors. This is particularly interesting because following Intel's tick-tock release cycle, according to the report, both of the platforms will share the LGA1150 socket. Earlier rumors and reports indicated that Intel's upcoming 'Broadwell' CPUs would feature a BGA socket, not an LGA socket.
The problems with backwards and forwards compatibility are being blamed on differences in the electrical connections, particularly with regard to power distribution throughout the chipset and motherboard.
While this rumor might be moderately concerning, Intel has planned to roll out a new series of refreshed 'Haswell' processors in the future. This is also a disturbance in the tick-tock release cycle. Expected changes include features that are catered more towards the feature set of the 9-series chipsets, with new features such as SATA express, and a very limited number of reports are indicating DDR4 support. From the report, we can also conclude that the 9-series chipset is catered to not only the 'Haswell' refresh CPUs or the 'Broadwell' CPUs, but rather to both.