I saw this when I check my data balance today.
In the past (well, at least a few days ago), it won't tell me how much data will expire when.
Makes me think... is roll over data coming to Skinny soon? =-)
Although, this could just be saying you have a total of 477.30MB, and 477MB of that is going to expire on the 12th of August, As in If you had multiple data packs that expired at different times