Rather than repeat what I have said earlier ...
Dear old Rex Mossop would have loved that one.
Can one of the older posters give an opinion of what the bodies of the forwards will look like with a different style of scrum. Will props need to be bigger, smaller or the same. Will the forwards of 2011 be suitable in a new scrum or will we see a new shape to the forwards?
Will this be the end of a mobile prop and hooker?
I don't see why it should change a lot. Props will still need to be big to exert power after the put in. Maybe power is the wrong word technically, maybe we should say "applied strength" instead. Props are bigger now on the average than in the 70s, but so are the 2nd row and the backrow. Then, as now (once the hit is over), technique played a huge part in scrum success.
I don't know why the present day props should not succeed as its the same as it is now when both sides have exerted a perfect power hit and the tunnel is in the same place. Teams that have perfected the timing of the hit will be disadvantaged, though in the past the timing of the power push was critical after the ball was put in. It was a pack effort then too and when one team didn't get the timing of the push right and the other team did, they would find themselves back-pedalling. The difference was there were fewer collapses.
Therefore you would expect that packs who got the power hit timing right would get the timing of the power push right.
As for it being the death of the mobile prop and hooker: mark my words - in the NH they will be making the counter argument that those bastards in the SH (read "Australians") want to do away with big guys and the game will lose its precious gift of being a game for all shapes and sizes.
It won't be all roses. The old props have to be involved in creating a scrum ELV and there has to be a protocol for the soft engage because coaches will want their front rows to be in the optimum position for the power push and there will probably be resets as front rows stand up because something isn't right.
There will be a lot of free kicks for this event in the transition period just as there are now for delay in throwing to the lineout, but they should become minimal over time.
And there will still be scrum collapses, especially when one team gets the power push right and the other team doesn't. It won't be the same as in the old days when amateurs folded in and did their power pushes. They didn't have the time to train in the gym anywhere near as long as the modern pro player does now; so they weren't as strong. There are other differences too that impinge on the scrummagers of now and then - you could start a thread on the subject.
But, with all these disclaimers and maybes, the scrum deserves an ELV just to see if the going back to the future is the way to go.
Maybe it isn't, but let's see.