Here's the short version: X99 chipset, quad-channel DDR4 (2133 MHz), 6 or 8 cores with Hyper-Threading, up to 3 GHz, up to 140W TDP.
Haswell-E, the replacement for recently launched Ivy Bridge-E, will hit in Q3 2014. VR-Zone China has already got their hands on an engineering sample but has yet to do any form of benchmarking. I went enthusiast and all I got is this lousy picture.
Image Credit: VR-Zone
Well, they also got the slide embedded above. Apart from the specifications that were highlighted above, the slide also claims that both the X and K series will be unlocked for overclockers. Especially given how resilient modern processors are, it makes sense to allow all enthusiast-branded parts to be pushed over stock settings.
Of course Haswell-E should also bring the long-awaited boost to single-threaded performance without compromising on the core count. It is expected to launch Q3 2014.