It doth seem that per the main python.org site, Python 3.0 (aka Python 3000, aka "WHERE IS REDUCE?", aka "There's a GIL?") is out and available! Hoorah! If you want to know what's going on hit up the newly formatted "What's New?" docs (they use the new-style docs) and read up.
For code conversion - you're going to need the 2to3 tool from subversion linked off the py3k page.
Test, test and re-test! File bugs! This is an alpha - the final is slated for August 2008 (per the page) so remember, no warranty is implied here.