I use Nokia phones since about 10 yrs, almost entirely thanks to opensource OS, so far I had 6 models (currently N900 + N6-01) and a half dozen purchased Nokia phones for friends.

If Nokia moves to proprietary OS Microsoft windows for its phones, then that definitely would be the end for my Nokia loyalty at once. I would never trust any Microsoft product whatsoever for any important communication.

A life without phone is possible - I enjoyed that for more than a year just for fun - a mobile substitute for the N900 (future Microsoft version) would be any small laptop or netbook Linux compatible.