I am reluctant to put things for safekeeping with a service that might fold any day without warning. I have a server, which backs up my laptop daily (and would back up any other computers on the network, although there are none at present). I feel much safer with that than with something in cyberspace.
I'm using Google Drive, mainly because I use Google Docs (merging with Google Drive anyway) and for hosting files I'd like to access from anywhere with any device. I do not think Google will fold any time soon, but I do share others' concerns about privacy. I would not store anything there with sensitive or proprietary information unless it was encrypted.