I will stick to doing what I have done for several years now - only sending cards to the couple of people who I know would be upset if they didn't receive one from me, and a couple of others who I want to keep in touch with but have no email address for. One of those who would be upset not to get one from me is my elderly mum, even though she will be staying with us over Christmas itself.
Unlike many of you, I actually hate displaying Christmas cards now. Our tiny house really doesn't lend itself to it - the window ledges are too narrow, as is the mantelpiece, and there isnt room for any sort of furniture that they could be stood on. Wherever I put them, they just look messy! I've taken to putting most of them on top of the kitchen cabinets though they do keep falling off when a door is opened. I make an exception for any cards from the immediate family purely for my mother's sake. As I said, she stays over Christmas and would be quite upset if those were not on show for her to browse.
I prefer to get catch-up emails (or similar) from people who I rarely see but don't want to lose touch with.