I, too, am interested in the replies to this question. I've read everything I can find on the subject.
I'm considering the Canon iPF 5000 and the new HP offerings. At first blush, it looks like HP is really going after neutral black and white printing. I've been tempted to get an HP 9180 for black and whites up to 12x18 until I decide whether the Canon or the HP Z3100 is the way I should go for larger color prints. It's likely that 16x24 will be large enough for my needs for a while (though I'd love to print larger at times), so that keeps me thinking of the Canon. Of course, then I consider both the smaller HP and the Canon 5000 since the HP 9180 is pretty affordable and my b/w needs tend to be 12x18 or smaller.
Man, this is a frustrating period for those of us in need of upgrading our printers sooner rather than later.