According toXfastest there will be four new processors under the new High-End Desktop (HEDT) banner for Broadwell.
Of the range, it would appear that the Core i7-6950X is the most interesting. It has a 10-core CPU with Hyper Threading, which means that it has 20 threads to play with and 25MB of L3 cache.
However the CPU clockspeed is a little on the slow side, running at just 3.0GHz. This will be a problem with software that is not properly tuned to take full advantage of large core counts and threads. It will be behind the Core i7-6700K which is a quad-core Skylake processor clocked at 4GHz to 4.2GHz on Turbo. The Core i7-6950X has more L3 cache, but it might lose to the Devil's Canyon Core i7-4790K which can manage 4GHz to 4.4GHz.
For those who like their clockspeed, Chipzilla will release two faster-clocked six-core Broadwell-E processors and an eight-core CPU that strikes a balance between clockspeed and core count. The specs that Xfastest found show:
Intel Core i7-6950X: 10 cores, 20 threads, 25MB L3 cache, 3.0GHz
Intel Core i7-6900K: 8 cores, 16 threads, 20MB L3 cache, 3.3GHz
Intel Core i7-6850K: 6 cores, 12 threads, 15MB L3 cache, 3.6GHz
Intel Core i7-6800K: 6 cores, 12 threads, 15MB L3 cache, 3.4GHz
All of these processors will have a Turbo clockspeed, though information about this is unavailable. All socket LGA2011-v3 CPUs should be compatible with existing X99 Express chipset motherboards.
As far as leaks go, it seems particularly credible to us. No word of price or release dates yet though.