I noticed this on my brothers phone last week, a Wildfire S.
Now its started happening on my Galaxy Nexus (Rooted, Stock Rom - Android 4.1.2)
It appears when apps try to update they fail to retrieve information from the server, as can be seen in the screenshots below.
Is this a know issue? i've not been able to update any apps for around a week now, either on 3g or Wi-Fi.
Excuse the large pics.