This morning the Google Nexus S phone I'm trying had a Christmas present: an update to the 2.3 Android OS, to 2.3.1. Install? Of course.
And when the install had finished, the phone was ready. And all the settings - mail, camera, locations of icons, downloaded apps, everythingexcept the SIM (thankfully) wiped.
So be aware: it's not a good install if you're using a Google Nexus S, at least, If you've had problems too with this Christmas update, do tell us. The problem may be because the Nexus S doesn't have separate storage.
The simple option: don't accept the update. We hope it was a huge mistake that will be withdrawn. But for those who have spent money on apps, that won\'t be much recompense.