According to VR-Zone and perennial rumour-site Expreview.com a target release date for Intel's upcoming Haswell-E CPUs has been revealed via leaked slides. The translation is somewhat imprecise however, and either refers to September 2014 or the 14th September of this year; based purely on the slide shown we'd have to opt for the former.
Haswell-E is expected to fit the LGA2011-3 socket on board Intel's X99 motherboard, preliminary models of which were on display at Computex2014. The platform is also the first to make use of DDR4 RAM, which provides for higher overall bandwidth as well as lower power consumption. The wholesale change of socket and RAM will likely necessitate a near complete overhaul of the systems enthusiasts will be upgrading from.
MSI's X99 Motherboard Concept
Three Core i7 SKUs should form the basis of the first round of Haswell-E processors: an eight-core i7-5960X (20MB Cache, 3.50GHz), six-core i7-5930K (15MB Cache, 3.70 GHz) and six-core Core i7-5820K (15MB Cahce, 3.60GHz); in common with Ivybridge-E each are built on 22nm architecture and support hyperthreading. As for prices... expect them to start at 'hefty' for the 5820K and increase from there.
Sources: VR-Zone China, Expreview.com