While they might not suit every live show, Dante-enabled comm solutions like this new Model 371 Intercom use AoIP technology for even the most basic of live audio tasks.
Slate's Media Technology department have developed a monitor controller for their RAVEN systems, or as a standalone unit. 'Control' is shipping now.
Have Behringer just released a monitor controller and interface at an X32-style price point? Introducing the feature-rich CONTROL2USB.