There are no exact dates of Coffee lake release but the idea is it will release Next Month. The leaked specs are below for now:
Intel Core i7 8th Gen:
TBD base/boost clock speeds
6 cores, 12 threads
1.5MB L2 cache (256KB per core)
12MB L3 cache
Likely LGA 1151 socket support
Intel Core i5 8th gen:
3.5GHz base clock
3.5GHz boost clock
6 cores, 6 threads
1.5MB L2 cache (256KB per core)
9MB L3 cache
Likely LGA 1151 socket support
It will be a very tough competition seeing Ryzen, the giant of AMD producing fantastic results.