Google has released a new build for Android 2.2 (Froyo) on the Nexus One; Build FRF72. It’s unclear what exactly is in this build. Some are saying it’s faster yet and offers better battery life. Apparently some internal memory has been freed up as well. One thing is known, protected apps have disappeared from the Market. This is pretty common with new updates and ROMs. I’m sure they’ll be back shortly.
If you’re rocking a non-stock recovery, this update won’t work for you. But you can go back to a stock recovery. Read through the post over at XDA for help. There are a lot of great folks there posting some very useful information.