From the limited information we have now, it sounds like a glorified Squadron system. FFXIV already has two seperate systems for combat npc joining us: Squadrons and Companions. Rather than adding a third, I'd prefer for all three to be merged into one master system that keeps all battle npcs under one roof. Allowing chocobos, squadron members, and whatever trust npcs there are to join us in any content, have skill trees, customizable appearance, etc.
But for now, the Trust system isn't something I'm looking forward to. Sounds like it will be another over hyped and under delivered system that's only slightly different from what we have already.