Is it in sync with the original project on Google Code?

Is it a fresh copy of V8? The home repository is on Google Code!

Yes, this code is fresh and kept fresh. The code is imported from Google Code, merged properly here, and then committed---with the PPC part---to Github. Git is the future, but V8 was hosted from the outset on SVN. git-svn allows this magic to fetch and merge the code from SVN into a Git project.