The formally organized demos increase the cost to participate. However, I still think that an interoperability demo can be done. In the past we have done "ad-hoc" demos. Network vendors would bring switches, would run a cable to each pod. Participants would bring what they want and make connections to the other participants as they could or just demo what they wanted. Groups of participants also self-organized demos among themselves. That is how it worked in 2006. It worked good too. If something didn't work it wasn't demoed.

I think IEC 61850 works pretty good overall and we don't need a big elaborate plan to put an interoperability demo together.