Re: Can somebody help me out?
Hmmm.. well, as you can imagine, there are going to be 100 different opinions on why they switched. At least some of the reasoning was based on GP's desire to win over some of the upstart WSB fanbase. Witness WSB's rant about it when the plans were first being discussed back in like '98 (I can't recall the year for sure.. it was 3 or 4 years ago). WSB sees this as stepping on their territory since GP's were all about 2-strokes and 'ultimate, unlimited motorcycles' and not about anything even remotely related to 'street-bikes', at least not directly.
Surely, the move to 4s will be touted as a way to capitalize on development of more "street-worthy" technology. There is more than a shred of truth to that, but not much more, IMHO. That's like saying that because Formula 1 cars are four-strokes, that we'll have engines and transmissions and so on that resemble those exotic pieces at some point. I, for one, never ever expect to see pneumatic valves on my passenger car vehicle any time before the supply of oil runs out!

And before anyone says it... the 'paddle shifters' that are found on a few passenger cars out there today are little more than remote controls for a typical automatic. As far as I have read, only the paddle shifters in a few Ferrari models actually shift a 'real' standard transmission, and not just some smart slush-box.
F1 surely fuels thought and development, and of course "racing improves the breed", but certainly race series that are spec or even silouhette based provide a bit more of a direct 'spin-off' opportunity than the highest, most advanced forms of the sport. I suppose you could say that the highest form of the sport is like 'far flung' research that may or may not trickle down. Probably as much DOESN'T as does though.
So, I guess it boils down to whether you really believe that there IS going to be significant "trickle-down" from this. I think there will, but it will be both slow in coming, and less impressive than anyone is hoping. Yes, I saw the 'computer depiction' of the street-going 211v in the recent Cycle World mag (and whatUP w/Burns being added back on to that staff??), I also have an issue of Cycle World from about '97 or so that had a street-going "vision" of an NSR500 2-stroke bike, ostensibly to "fend-off" the challenge of the Bimota Vdue that was fresh off the press at the time. The Vdue actually 'happened' and was, unfortunately, just too under-developed and under-funded... a flop: thereby damning the chance for a new 2-stroke street bike forever. The Honda was just more FUD to stall off competitors.
The twins thing dominating is simply a statement of "fact of the moment". Since they get a cc-break (1000 vs. 750-4's), they 'win', simply stated. There's movement under foot in WSB and AMA (I think?) to let what amounts to SuperSport 1000cc 4-cylinder bikes compete w/1000cc twins. The important distinction being that the inline 4's only get the type of mods available to super-sport where the twins still get the more 'free' rules of superbike. For a detailed list of exactly what those rules entail, seek the websites of WSB and/or AMA... they generally fall into the categories of how much cam/head-work/pistons can be done or altered.
-James