RHEL 7 seems to have dropped installer / native support for 32bit Intel x86 machines. Only 64bit machines will be supported, and there is 32bit multilib support built in, so people can still run most 32bit apps.
So do we want to build a 32bit installer and os tree for CentOS-7 ? Can we find the people and resources ( mostly people, resources for an extra os tree are minimal in this case ) to be able to maintain that 32bit tree ? Large part of the answer would depend on what feature set we intend to support ( likely wont be a 100% cover of the x86_64 spec ), and what the real user demand for this is.
Update: Its worth noting that we might need to build a i686 tree in order to build the multilib components in x86_64 anyway.