I'd like more details on what the French and English clubs are doing that the IRB needs to punish.
If they are supposed to release players outside international release dates, then what are international release dates for?
Hansen is a senior NZRU figure, Cannon is in sports media. Hansen didn't quote Cannon, he restated his controversial claim in all seriousness. That's not acceptable for a leading coach.
One of the fitness requirements for sevens which coaches look for is repeatability. A speed merchant will often need to accelerate and go flat out only moments after he's just done exactly that. It's less of a requirement in the fifteen man game. Some players naturally have that kind of engine, while others need conditioning.
I don't think anyone doubts that many top players can make the grade at sevens. The argument seems to be mainly about how long it would take to get back to performance levels in the shorter code. Mike Friday says 10 weeks while another coach quoted in today's UK Telegraph thinks two tournaments would do the trick.
The window is probably between the end of the 2015 World Cup and Rio, which raises another issue. If the World Cup succeeds in boosting rugby's profile, is it really helpful if top stars immediately drop out of the fifteen man game at club and international level?
The IRB has said that the sevens World series next season will come under regulation nine. If teams select players, then clubs will be obliged to release them. That's probably more of an issue in the North, where teams have overseas players from most of the countries expected to be in Rio. The World Series also runs from October to May, so every tournament overlaps with part of the season on the North.