I've been giving this some thought, and I reckon a pre-season Sevens comp would be awesome. Rather than having IPL style franchises, though, it should be international sides. There are at least 20 countries ranked by the RLIF who never get any real exposure on the world stage, and who may not be up to fielding 17 players against some of the better RL nations but would hold their own in Sevens.
The other benefit is that transporting a squad of 10 players is a lot cheaper than a squad of 20.
Just picture, say, Brisbane and the Gold Coast hosting a February competition involving not only Australia, England, NZ, but also Scotland, Wales, Russia, PNG, Samoa, Tonga, the US, Serbia... put enough prize money on offer that it covers most of the expenses of each team. Fox Sports to televise, professional clubs to get a glimpse of some of the talent in other countries. It would be a fantastic way to grow the game on an international level.