Much of what you say I fully agree with. We do differ when it comes to the MP of a recombined 1D range body or whatever Canon choose to call it. To me 30mp is about 3 years too late to make the grade as a top flight pro camera. Other manufacturers are openly talking about 40MP and I suggest that for Canon to have any claim at all to the top step of the podium they must at the very least match that.
I'll leave it to the tech geeks to discuss why 40MP is technically difficult or impossible to achieve for this size sensor. What I will address, or rather ask, is what the heck would you do with all that data? Is there really a practical use for 40MP or are we all for some reason obsessed with seeing the fulfillment of the prophecy of Moore's Law?
This is strictly my opinion of course, but anything much more than about 25MP is just irrelevant to my work. The 18MP that comes out of my 7D's are already overkill for many applications and some clients actually request that I and other photographers provide lower rez images so as not to overwhelm their archive systems. When you're doing web design and small trifold brochures and in-house newsletters, even 11MP (the next "standard" size down available from the 7D in Adobe Camera Raw) is overkill, but at least the file size is more manageable.
Storing all those Raw files is no picnic for me either, but of course I deal with it.
Put another way, I can do a reasonable amount of cropping and still get an excellent 13x19 portfolio print (max size from my Epson) from the 7D. The 5D would of course do better, and future future iterations of both of these cameras and the 1D will undoubtedly improve even on that. But 40MP? Just sounds like a lot of pixels I'll never really use except for maybe .01% of my images.
There is of course the limited market for commercial and very high-end portrait/wedding work that will want those megapixels for retouching and/or bookcase-sized enlargements, but don't the vast majority of us just want to get off the megapixel treadmill and start seeing some better performance in low light?
Can I get a "hell yes" from the congregation?