OpenOffice.org 3.0 Final has already been uploaded to a variety of mirror download sites ahead of the official announcement Monday 13.
The official list of download mirrors can be found here. Note that not all mirrors currently offer all OS flavors of OO.o 3.0.
The path to the final download is usually as follows: stable/3.0.0/
Release notes have yet to be updated from Release Candidate 4.
If you want to be ahead of the curve, grab a copy now. If you are cautious, wait until the official announcement on Monday.
I'll be putting OO.o 3.0 through its paces later.