EVGA, joining a number of other motherboard manufacturers, have today broken cover to announce support for the upcoming refresh of Intel's 4th Generation Core AKA Haswell CPUs on their current Z87 motherboards. Although we don't have a firm ETA for the launch date of these CPUs beyond this quarter, EVGA are nonetheless stating that their own Z87 motherboards will be compatible with the new CPUs following a UEFI BIOS update, available direct from their support microsite.
Unfortunately, perhaps because a cagey approach to Intel NDA, no manufacturer has yet been able to state outright whether or not Z87 would be compatible with the Devil's Canyon CPUs - unlocked 'K' variants of the Haswell Refresh due some time after the initial launch. The best information we currently have, which is certainly not official, is that these CPUs will only be supported on Z97 motherboards. Food for thought if you're planning a piecemeal upgrade process rather than getting all your components in one batch.
EVGA's Support Page can be found here, which also includes instructions for updating your BIOS.