Did you recently change your domain name servers? Your Jetpack connection seems to be broken at the moment, and something seems to be wrong with your nameservers.
Could you try to disconnect / reconnect to WordPress.com in the Jetpack menu? If that doesn't help, can you please try installing the Jetpack Compatibility Plugin so we can see some additional information from your site?
1) Download the plugin from http://plugins.svn.wordpress.org/jetpack/branches/jetpack-compatibility-test.zip
2) Upload the plugin to your site via Dashboard -> Plugins -> Add New.
3) Activate the plugin and go to Plugins -> Jetpack Compatibility Test.
4) Click the "Select All" button.
5) Send us the test results via this contact form: