CCP has released a little more information on their new structure direction.
The first ones they are working on are Citadel class structures, which are Market and Office Hubs. The choice sounds a little strange at first, but their focus is on asset safety, protection, and a feeling of home. They are fortified bunkers equipped with weapons.
Within the Citadel group, they will begin with Medium (Solo / small groups) and Large (Corporation / Small alliances) versions first. They suggest what sort of armaments will be able to be fitted, and remark on what will be useable in Hi-Sec, and what won’t.
It is certainly an interesting concept, and I am guardedly enthused.