Z87E-ITX owner, looking to upgrade.

Unless you want to go for a socket 2011 setup, nothing. The Z97 will offer support for Broadwell which from all indications so far will be restricted to an i7 and i5 model and nothing more. More than that, the Broadwell CPUs will offer little to no performance over Haswell. You would be better served waiting for Skylake to hit the shelves, Asrock already previewed an intel 10 series motherboard recently in anticipation of Skylake release. 

Xaltar wrote: Unless you want to go for a socket 2011 setup, nothing. The Z97 will offer support for Broadwell which from all indications so far will be restricted to an i7 and i5 model and nothing more. More than that, the Broadwell CPUs will offer little to no performance over Haswell. You would be better served waiting for Skylake to hit the shelves, Asrock already previewed an intel 10 series motherboard recently in anticipation of Skylake release.  So I would say wait a few months and look again

I agree, but it seems like the OP was looking for a board to use with his current processor. Intel 100 series chipset boards use the new 1151 socket for Skylake processors, that is not compatible with the Haswell 1150 socket processors. I may be wrong about the OP...

I also haven't checked if Skylake processors abandon the Haswell integrated VRMs on the processor itself. I recall hearing that Intel might do that with Skylake. Not to mention if mainstream Skylake processors go back to the use of solder between the processor die and IHS, rather than TIM, which has been used since Ivy Bridge.

Enthusiasts seem to think that Skylake processors will be like Sandy Bridge, which gave us a large increase in IPC. I hope so, Sandy Bridge was a gift from Intel, possibly too good in their eyes, as it made the HEDT processors much less attractive to users. I've always thought that is why mainstream Ivy Bridge and Haswell processors were partially gimped by the use of TIM instead of solder.

I would hazard a guess and say for the 1150 platform the Z97E-ITX/ac would be the best ITX board on offer from Asrock at this time as it has better power delivery than the Z97M-ITX/ac model which should yield more stable power.