GNOME 3.8 is a great release, with a bunch of neat new features. I like the new method for opening the notification bar - it opens instantly as long as you hit the bottom of the screen hard enough, but doesn't open at all if you just nudge it - and the improvements to GNOME's 'online accounts' stuff are awesome: you can set up email and Owncloud accounts right in the GNOME control center, and they get picked up in your Evolution and Nautilus configuration. For the traditionalists among you, GNOME 3.8 comes with the new 'Classic' mode (though I have to admit, I didn't test that at all!)
At the Test Day, we'll be working to find any remaining bugs in the latest GNOME 3.8 packages. It's easy to join in - we provide a live image for you to test with, and full testing instructions on the wiki page. You can join other testers, QA team members, and GNOME team members in #fedora-test-day on the Freenode IRC network to discuss your results. If you're not sure how to use IRC, we have some instructions here, or you can just click here to join through a Web front end.
Fedora 19 is still pretty early in development, but we've done our best to build a live image that will work as smoothly as possible for the Test Day. So if you have some spare time on Thursday, please come along and help make sure GNOME 3.8 is as good as it can be!