I just upgraded from JetPack 1.1.3 to 1.2.1 on my site. I am using several of the new widgets without issue but I can't get the Subscribe widget to work. We had been using Subscribe2 6.5 plugin but wanted to switch to the official widget. When I attempt to subscribe an email using the sidebar widget on home page the response is to /?subscribe=error#blog_subscription-3 and says "There was an error when subscribing, please try again." on the sidebar. I haven't yet unistalled the Subscribe2 widget until I got this one working if that matters.
Another related question once I get this working. I see that in the dashboard there are users and one type of user is subscriber. Then under stats in JetPack there are followers. I don't think they are the same, but are they related at all?
Lastly, in my JetPack feature page with the bubbles for each widget I don't see a deactivate button until I click Learn More on an item. The activate button is available however.