It's looks pretty, and the idea definitely has a future, but sometimes these technologists forget that we are multi-sense, multifunctional humans. Sometimes I'm not looking at my phone when I'm using it, and I think this is human nature. I think an item that demands you always look at it to use it will be perceived as intrusive, either to the one using it, or to the one who has to stand and wait while this item interjects in their interaction.
I wonder if this will go the way of the thumb operated trackball mouse, etc. It is amazing how common thumb arthritis is, in fact very few people realise they have it until some thumb dexterity is required.
I'm not happy with the apparent response time of the phone's menu system either... or maybe I'm just in a grumpy mood today...

Just be a nutter... life becomes much more exciting, and people won't expect anything more of you...