Ever since I read this thread, I can't get the idea of a pony play convention out of my mind. It's such a wonderful idea, and in the two months since the idea was floated in the Fetlife pony play forum, I've let my imagination run wild with the original poster's idea.
The following is the result of my musings and fantasies on the concept:
Imagine having hundreds of pony players in one place for a multiple day convention dedicated to pony play. There would be displays from all the equipment vendors. You could watch pony play demos that covered every discipline from dressage to jumping to reining to roping - illustrating everything from the most basic training through to the most refined of human pony movements in that discipline.
There would be talks on various aspects of pony play and plenty of time for ponies and trainers to meet each other and network. Or to play - there would be plenty of space available to play and extra carts available for potential cart ponies to try out. We could even have some friendly competitions for those interested. Perhaps we could even have a live band in the evenings that would play wearing full horse head masks.
And if you weren't able to make PonyCon 2014 in Seattle, you could catch PonyCon 2015 in Melbourne, or 2016 in London, or 2017 in Cape Town, or 2018 in Berlin, or 2019 in São Paulo, or 2020 in Venice.
The event would, of course, be free to attend: no admission fee, no tickets, just show up at the door.
While, I would love nothing more than to see the idea of PonyCon turn into a reality, I think it would take more than simply money to get it off the ground: it would take the cooperation of vendors, speakers, demo ponies and handlers (from multiple disicplines), and, of course, a large percentage of the pony play community.
I do hope there is a PonyCon in the near future, but for now, at least, I have the catharsis of giving voice to my imagination.