In the last ten years or so the beautiful icon of Bookends was always hosted on the dock of my mac. Now, with the downgrade to Yosemity, the bookends' icon looks like awful!!! After the conquest of 3D now we are regressing to 2D (!). Please, Jon, give us some sad flat icon (I suggest something like that of the new iBooks app, eventually with other colours). For my mourning I dismissed the beautiful Apple desktop pictures, and adopted a dark grey solid desktop: the downgrade is accomplished.
I think the icon still looks fine, but agree it's out of step with Yosemite. Changing all of our icons isn't a trivial step, though, so it may take a while before we get around to it.