I'll add my story to the others in this thread. I worked for 18 years on renewable contract and, suddenly when I was 58, my employer decided that I wasn't needed anymore and "didn't renew" my contract. To make matters worse, he sent an email to the whole department saying that I was leaving because I'd decided to seek job opportunities elsewhere. I would have loved to work until retirement but ...
Another point: if I hadn't been let go, the person that replaced me (who is at the beginning of her career), would not have been hired. Keeping the seniors employed while locking younger people (who will be paying the taxes the seniors will no longer pay) out of the work force isn't really a solution.