There isn't a release date yet. Every rumored date gets pushed back. The most recent was a July 13th date that is now pushed to 'August'. This is all hearsay, though.
Only way to currently get 2.2 is if you are rooted and install either a vanilla build of 2.2 or a custom ROM built with the 2.2 source code.
As soon as the official update hits, expect the 'update.zip' to be all over the web within the first day, then we can all download and install it (rooted or not).
- How to root a Droid running 2.1
- Once rooted, download ROM Manager from the market. This app will download and install many different ROMs for you.
NOT RESPONSIBLE FOR ANY DAMAGE :)