The 9-Series chipsets will be accompanying the next-generation Core series of central processing units, called Broadwell. Unfortunately, that might be all they can do.
A report published by VR-Zone made some worrisome implications about the successor to the 8-series chipset line.
Despite the socket being the same (LGA 1150), a number of electrical connections between the CPU socket and chipset are different.
Broadwell also follows a different power supply than Haswell. Which is to say, the power distribution within the chip/motherboard differs.
These differences could impair backwards-compatibility. In other words, current-generation Core i3, Core i5 and Core i7 Haswell CPUs might not work properly, or at all, on Series 9 motherboards.
We'll see for sure in the second half of 2014, when Broadwell and Series 9 debut. Or maybe we'll get lucky and the issues will be solved long before then.
On the flip side, Intel is preparing a Haswell refresh to fill the time gap between now and then. Broadwell may very well be more compatible with those chips instead.