May be I'm missing something obvious but... I can't see my tasks neither in Windows 8 Calendar application nor in web version (which is synced with Windows 8). By the way creation of tasks is available only in web version. But after I've created it I can't see it anywhere at UI.
In the website, you can click on "view" in the upper right corner and select "tasks".
However, I am still looking for a Metro app too.