...Google finally released an uploader designed just for Linux.
The uploader essentially works just like the Windows version, with one
small tweak: OGG support. OGG files will automatically be transcoded
to 320kbps MP3 files, which will inevitably make the already painfully
slow uploading process last even longer -- but hey, at least you can
finally use that beta invite, right?
To grab the uploader, head over to the Google Music Landing page, hit
'Download the Music Manager', select the appropriate package based on
your Linux distro, and install.
Hope they are useful. Read comments. Remember to edit: «GMAILUSER -p PASSWORD -s /path/to/music -m SERVERNAME» with you own data. (SERVERNAME could be whatever. Its just a name so you can identify your server from your Google-login.)
Type $HOME/gmm-headless-script.sh in terminal to start sync.
Edit: some systems won't already have Xvfb installed, and on those you can fix this with sudo apt-get install xvfb.
Best Answer
You can now.