Here is a work-around.
Start in your Google calendar, click the down arrow next to the calendar name to see the context menu. Choose "Calendar settings." Next to "Calendar Address" click the ICAL icon to get the URI for that calendar. Copy it.
Now open your Hotma..., um calendar.live.com calendar. (Remember the new branding!) Click the "Subscribe" link above the "Month" tab. You want "Subscribe to a public calendar." Paste the URI in the URL text box. Give it the same name as it has in Google. Click the "Subscribe to calendar" button.
Wait for your "Live" calendar to import and for your Windows 8 calendar app to sync. It worked for me!