I'd rather have it stick to movies.
When the 2010 Winter Olympics ended, I was so mad and frustrated and sad all at the same time. I asked my guardian to call the olympics so they can have one month the summer olympics, and the next month winter olympics, then repeat, forever.
He then lectured me on why and how the olympics is so great, the fact that all the waiting and preparing has come to an exciting 2 weeks of celebration and cheering and all these countries in one place. Now I really understand what makes the olympics special. Because it's only 2 weeks every 4 years. It's like a holiday sort of.
Equestria Girls is roughly like that (Even though I don't really like EG )
So for it to be a show instead of a yearly event, it won't be as special as it is at the moment.