I think it's really too bad that you have this frame of mind. The fact of the matter is that it's already been announced, and confirmed among major cellular carriers including Verizon, that this update will be arriving in early February. So be a little more patient, because the Icon will be getting Cortana in the next few weeks.
As for everyone railing against Verizon, keep in mind that they do all of this, for YOU. They want the experience that a customer gets to be so phenomenal, and bug-free, that they test the crap out of not only software updates, but new phones in general, to make sure it lives up to their standards. This is so that when you do finally get the new phone, or the update, you won't have to go through all kinds of hassle because something was overlooked and now your phone isn't working and as a result you've missed an important business call, etc. Is it sucky to have to wait? Sure it is. But would I rather a top-notch, properly working bug-free product? Definitely. It's like when a gaming company delays the launch of their new game so they can work out the bugs they found. Gamers hate having to wait longer, but when the game finally launches and it's a gorgeous game with little to no issues, it was SO worth the wait.
[End of rant]