One thing that I think makes a huge difference is having Skype through a camera on the television set. This means that instead of sitting in front of a computer, you can interact with people from your sitting room. We are able to do this with one set of grandchildren and it means we can really be a part of their everyday lives.
I think in old age and infirmity it could help with isolation, but also give a means of interaction with doctors, social workers, friends, family etc. So high quality wireless broadband everywhere, hardwired into the home and video links via television screens is my first suggestion. When I used to go on ICT blue sky events we used to talk about things like clothing that could detect illness, toilets that could analyse deposits and so on. Not sure how far any of this has got now.
Misguided charlatans? - mediums
Sneaking away - goodbyes
Not going out - ageing