The main premise here is "Apple did not update its desktops in a while, so they don't care about this". I think this is inaccurate - according to http://www.macrumors.com/roundup/imac/ , they do plan to update them, but are still waiting for Intel to produce the necessary chips.

Also, I seem to remember reading pretty much the same thing before the Mac Pro was launched (which was apparently 1046 days ago...).

So yes, desktops are becoming less important, but no, I don't think Apple will drop them any time soon.