Will new Intel CPUs be compatible with 1151 socket?

Solution
Probably yes, with a BIOS update. But I see no reason to upgrade from Sky to Kaby. Cannonlake is a different story, but you'd need new board for it.


But isn't Cannonlake delayed until 2nd half of 2017?
 
If upgrading to an equivalent model, then I'd agree. But if you're upgrading from like a Pentium -> i3 or i3 -> i5 or i5 -> i7, then you'll get more benefit from also upgrading generations.