As a few have pointed out, keep an eye on league players trying 7's, especially in a few years time when the heat gets turned up in preparation for a gold medal tilt. If a proper national comp or system was established with an olympic/15's pathway in mind, you might see quite a few try their hand at it.
Coming from a club that has struggled to put a colts side out in the past 4-5 years, anything that could assist in attracting players into the fold is worth looking at.
Personally, I'd love to see more 7's played over the off season. In Canberra, there is barely anything, aside from the Queanbeyan 7's which were held last weekend. It's so good for speed, technique and fitness - more enjoyable than hanging around a gym in my opinion.