Ok well after much debate I've decided to stick to my Haswell build for now and wait until Broadwell-E comes out to buy CPU/Mobo/Memory seeing as Intel will probably be releasing X99-V4 mobos to go along with Broadwell-E.
The x99 chipset and 2011-3 socket will remain the motherboard foundation for broadwell-e. Intel are not going to release a new chipset and the CPU socket with remain the same like previous generations of Intel's 'e' platform where there second generation cpu's on a smaller manufacturing process were a drop-in upgrade after a bios update. The 'e' platform wont see a new chipset or socket till skylake-e sometime likely now in 2017.
Curiously Intel will be releasing a new chipset for the consumer lineup refresh 'kablake' ala the z87 and z97 chipsets for haswell and its shrink to broadwell.
Back on the subject of x99 though..
given its just a die shrink and given that these have not recently yielded much in the way of performance improvement's I would not be expecting much more from broadwell-e over haswell-e except some power consumption/heat improvements. The main difference will be the lineup having a 10 core CPU at the helm rather than an eight core which is of of little relevance to most people.
The base line broadwell-e cpu replacement for the 5820k will likely have very little if any improvement in overclocked performance with just a mild bump in stock clocks.
Basically don't hold of on buying thinking that broadwell -e will bring something new to the table because it wont unless you really need or want a ten core CPU.
If i had been in the market for a high end pc recently I would have been all over the bundle deal ocuk had over the weekend for x99. You really would have to have your sanity checked if you shelled out for a 6700k setup when this was on offer.....