Unfortunately I am experiencing the same problem. When I select App Store, I am greeted with "Can't connect to iTunes Store"
I have searched my account settings and general settings to update my account info, as my apple ID that I use for the store is different than the one I use for iCloud.
I disabled passbook from iCloud and still won't connect to the app store. Reset my phone, closed out all associated apps, still nothing.
If I open the app store app it works just fine, as well as iTunes. It seems there is an error in the link or there are some account settings that need to be configured.
Someone let me know when you get it figured out.