This is a really nice post, actually. I have seen the new items and I've gotten really excited for these new updates. I myself main support, and so many of these updates are changing the role of support down bot lane. You pointed out a few things that I did not even catch. The second-hand buff to supports' movement speed slipped past my eye, and I didn't actually realize the possible importance of Wraith's Collar; especially down bottom when your Amumu (as an example) is trying to gank for you and you do not have any current vision of the bush. Now you can pop the wraiths and give him free vision. But looking at the items that build up to it. Sure, it builds from Kage's, a gp10, but a bit of AP, MR and movement speed might not be justified by the active ability.
Additionally, I want to point out that the new item Ohmwrecker could be the bane of supports. Due to the fragility of the bottom lane champs, the lane tends to be a common victim of the turret dive, and Ohmwrecker might become common on junglers like Amumu, Maokai, and Alistar. If so, bottom lane is going to be dove much more often.
Aegis might be better to buy earlier in the game, too. With the health regen bonus in place of the attack bonus it can give a lot of sustain to your ADC.
Sorry for the great wall of text, but I saw this post and it made me happy. :P I agree that people don't fully understand the importance of a good support, and you should know that this post alone encouraged me to create an account just so I could reply. I look forward to seeing further information on this page. :)