On the Android Developers site, Android 2.3.3 has gone live. From the looks of it, the majority of the update deals with new API's for Near Field Communication (NFC), adding reading and writing abilities, meaning this will most likely only apply to the Nexus S. The update also includes some new API's for Bluetooth, graphics, media framework, and speech recognition.
For those of you that are new the idea of NFC, it basically allows your phone to communicate with other devices with the chip and will be pushed in the near future to allow your phone to make payments instead of carrying credit cards around.
For those of you who want to manually install the API, check out the Android Developer's site. For the rest of you, there should be an OTA update soon.