I believe it's all of them. If you go to any of the fonts (from the Font menu drop-down), there's a new "Webfonts" tab at the top (next to "Styles") that allows

I believe it's all of them. If you go to any of the fonts (from the Font menu drop-down), there's a new "Webfonts" tab at the top (next to "Styles") that allows you to preview the fonts on the web. It seems to be there for every font, and it seems to include every weight and style.