In 2014, Canon needs to do three things and they will be just fine:
#1 Release the darn 7D2, and make sure it is a masterpiece since it took so long. 5D3 autofocus, articulating touchscreen, headphone jack, DPAF, etc.
#2 Surprise everyone with a 6D2 which is a very similar refresh of the 6D, only difference being addition of touchscreen and 7D1-class autofocus; maybe add a popup flash too for triggering and portable situations. This would differentiate it enough from the 5D3 as the autofocus still won't be as good and it will be missing other features, but it would make the 6D2 attractive enough for enthusiasts to pull the trigger. Right now the autofocus is too weak, and the touchscreen might entice people who are used to touchscreens on cameraphones.
#3 Release some of the more requested lenses, i.e. 50mm non-L IS, 135mm non-L IS, 100-400L refresh, 24-70L IS, 14-24L. I think those would satisfy most and continue to make Canon the obvious choice.
Personally I think the 5DIII does not require update as it is so strong. Canon's main weaknesses are the 6D, 7D, and some of the older lenses. It remains odd to me that the 5DIII and 70D are so attractive in their pricerange, yet everything between those two appears unattractive. Likewise, I find it odd that crop users have effective 24-70 f/2.8 range with IS for some time, yet Canon is still stringing along full frame users with non-IS lenses in this focal length for no obvious reason except marketing.
To summarize this post, Canon needs to gimp their cameras and especially lenses less. Yes, they should still offer differentiating features, but not so much as to make the product unattractive for many.