If you were following news related to Google Nexus S you probably know, how frustrating for the owners is the random reboot problem - the device can restart more than 5 times a day, without any reason.
Finally, Google decided to solve this problem. According to "Google employee", Ry Guy:
The initial results of our tests look very promising. At this rate we will most likely be rolling out an OTA to resolve this issue within one to two weeks. We really appreciate your patience as we do our final verifications on this fix before sending it out.