That's me off then...
OK, point of fact first - they've always offered a free 2GB service, in the usual Freemium way.
At the time I signed up, the unlimited package was a good deal (nicely discounted if you bought two years in advance), and more important, they had a working Mac client before some of their competitors. And it's worked well - backups work, restores work, and I've happily recommended them to anyone who'll listen.
I found out about this change via Twitter yesterday. About 24 hours before they sent me the email, which suggest that I need to pick a renewal plan (no chance).
I'm one of the "marginal" customers who stores well over the 150GB their new top-level service allows. And an extra $2 per month per extra 20GB would make the service far too expensive (cheaper to buy a new HDD every few months and store a full backup away from home).
I've got a year or so left on my package, so I'm in no rush to move. My concern is not that Mozy have given up on the unlimited package for a fixed price, others will follow.
Funny, you'd have thought EMC could afford some extra storage....