OSC is a communication protocol with greater resolution and bandwidth than MIDI and an open-ended URL-style address nesting (example: /synth3/filter2/cutoff 5.0000).
For software that supports it, it is very cool. I don’t see it being integrated for hardware very soon, because it nearly necessitates software integration so that you can define the messages being sent. For example, with a Lemur, you get an editor program wherein you define the OSC message sent by each object. (They do have defaults like "/pagename/containername/objectname x value", but obviously if hardware integration is coming, the destinations are likely to be pre-set on the receiving object, and defaults on the sending object will need to be modified.)
The nature of the address structure makes it very intuitive and easy to work with, along with the greater bandwidth and resolution.