I think the differences will be imperceptible to anyone but the riders. As an example; in top fuel drag racing NHRA has limited engine size, rpm,(rumor has it that some of the sharper tuners have figured a way to use the rev limiter as a sort of traction control) fuel percentage, tire size, in fact now they are all on spec. tires, and they are still faster. Racers are racers. The guys with money will spend what ever it takes and still go faster.
Re: Just one question, is someone sabotaging Rossis bike??
The Honda bikes are probably just so much faster that attempting to get that type of performance from the inferior Yamaha platform (which it has been since inception) has stressed it to the point where it's no longer reliable.
I recently read some old reviews (more than a year maybe - a lifetime, in other words) on the M1 and RC211V from some motomag that got to ride them and while their opinion is likely of limited value, they suggested that the RC211V had a lot more giddyup *and* substantially better handling. The platforms are similar, if revised, today, but I would bet that the gap has only increased.
Go back and look at Rossi riding a couple of years ago on the Hondas doing unheard of and ridiculous things, just blowing the field out of the water at will, and watch him struggle to keep up today. Same rider, but his bike just doesn't have the same performance.
He still is competing for the championship, because it's mostly rider, but bike makes a small difference. All of those guys are pretty much amazing riders, so sometimes, even the Doctor's genius isn't enough to overcome 50 / 50 equipment.
Will this lead to the rebirth of the 750's and 800's in the consumer market? Looks like the Brits (Triumph) are already on the cutting edge. Think they'll bore out the 675 to 750? That would be like the cherry on top of the sundae. Mmmm!
I'm not sure that I like this rule change. One of the intriguing things about this year's motoGP campaign is the diversity of riding styles of the various riders. Some riders seem to be more aggressive than others in the early stages, resulting in excessive tire wear and a slip backwards through the pack. Personally, I love to see the excessive power applied to these racetracks. It really challenges the technical limits of the bike and tires and also challenges and rewards the rider's skill. Somehow, the idea of more docile but competitive bikes doesnt carry the same cache.