The first generation of Intel processors to support the next generation of DDR memory is coming in 2014, but it'll be the high end variant only - the mainstream option sticking with the tried and tested DDR3 for a while longer.
Known as Haswell-EX, the 16 core chip will be available in four socket platforms allowing for a ridiculous ammount of processing power on a single mainboard. While DDR4 will add extra bandwidth to the equation, it will also help lower power requirements needing just 1.2v per dimm.
Designed more as server modules, it's likely only the most ardent enthusiasts will take the plunge there, most sticking with the much more mainstream 22nm Haswell desktop variant. The DDR3 it will support will still have an increased bandwidth over current offerings however, hitting at least 3000MHZ by that time (though it can be done now with some heavy overclocking and advanced cooling). VR-Zone (opens in new tab) believes support for DDR4 on this platform and its Broadwell successor chip will come around a year later.
Regardless of all this however, the real excitement at the moment is surely the impending launch of Intel's Ivy Bridge. This big die drop down to 22nm should see some nice performance improvements as well as the usual die shrink tweaks such as better power usage and a lower TDP.