Jason, glad you found the articles helpful . . . regarding your questions:
1) the frame lines within the viewfinder reach almost to the edge but I haven't had any difficulty composing with it. Since I use rangefinders almost exclusively, I no longer expect an exact correlation between what I see in the viewfinder and what is captured. A little approximation is always a part of my compositional process
2) The metering display in the viewfinder is pretty clever. A row of shutter speeds is displayed on the right side, highest at the top (1/500) down to the lowest. If you're shooting in Aperture Priority mode, then the shutter speed selected by the metering system is displayed (based, of course, on the aperture you have selected). But, if you are shooting "old style" (what I call "match needle"), then as you move the shutter speed dial on top of the camera, your selection is illuminated BUT the metering system also displays in a dimmer red illumination what it believes is the correct shutter speed. Pretty clever, actually. I like it. What I don't like is that there is no display of the selected aperture in the viewfinder.
3) I have no information beyond what I've shared about a release date for the 670W. Regarding the price of the GF670: I did a spot check this morning and the price is holding at $1799 and I won't speculate about further decreases. Since the announced GF670W is meant to be a complement to the GF670 and not a replacement, I don't think it will cause any downward price pressure on the GF670. My view on pricing is simple: I don't buy unless I am happy with what I am paying at that moment . . . if the price drops the next day, so be it. At the moment I purchased, it was to my mind a fair bargain.
Hope this helps,
Mark