Until now, I've been using various Google Fonts throughout this site's existence on Squarespace 6. I have a free Typekit account, but a lot of the typefaces I really want (such as FF Meta Serif Web Pro and Proxima Nova) only exist on the paid plans and I haven't opted to upgrade just yet.
Today though, those fonts and a lot of others have been made available for all Squarespace 6 users, thanks to a deal the two companies have struck together. This makes me pretty happy.