Edmund,
I understand. As for the general discussion here: To me, medium format is not just about quality. It's a certain feel and shooting style, and the available use of many different aspect ratios to minimize cropping while printing. I like using a big, awkward, and slow camera for many things. Even if Canon put out a 100MPixel camera that would give large negs a run for their money, it would still feel like a 35, and have the 35 aspect ratio, and thus be no replacement. If you want the 35 feel and composition with quality close to medium format, the new Canon may be worth considering...it'll be like a modern SLR version of the Mamiya Super 23 (one of my most beloved cameras). However, when I shoot medium format, I am after something else than just quality. I like the disciplined and restrained process of using the larger and slower equipment sometimes, and I really like being able to choose several aspect ratios with the same size of film. I have a 6x9 Mamiya, a 6x6 Mamiya, and a 6x7 Pentax. This gives great compositional selection without having to crop, as with 35. If you were to shoot a 35-style camera to crop for these formats, you would just reduce the quality even more. Shooting to crop is a real pet peeve of mine. It wastes quality and makes obtaining a nice composition a lot more difficult....for me, anyhow. I think that those who are looking for a medium format replacement from a 35-style camera are just lazy and confused when it gets down to it. They are after a certain shooting feel, which is a perfectly legitimate reason, but should not be confised with quality debates.
As for Annie Liebovitz... So-and-so uses such-and-such a camera is never a tactic that works on me...So-and-so is not me, and doesn't know what I want and prefer, and in most cases, so-and-so is working for hire, not for themself. If you have assisted for her, then you know that what camera she uses is not her main concern. The assistants do everything for her while she gets what she wants from the subject and trips the shutter. Early in her career, she would scream in excitement when picking up her film at labs just because something was on there at all. Her skill is with people and with concepts, not with photography, per se. I do not say this to minimize her work, but to make the point: Why would I look at what equipment she uses and even think about caring or about changing what I do? I can understand why she would make the switch from Mamiya to Canon digital...but I think its much more an issue of her current shooting style and of staying current than it is an issue of any quality consideration. 35 and MF are not the same things, and never will be. 35 format will always be the punk-assed red-headed step child of photography...and I mean this in the most loving way possible. It is a lovely format, and I use it pretty much every day, but has always been a shortcut to using larger formats. Not a shortcut witout use and without reason, but a shortcut nonetheless. There is way more to it than megapixel specs. I would never consider any camera with the 35mm feel to be a replacement for medium format, regardless of how many megapixels. All the new sensor will do is let those who love using 35 go bigger and/or get better quality at the same size. It's an advancement for 35 users, not a replacement for MF users.
All of this is childs play anyhow. 8X10 is where it's at.
KPL