Well surprisingly, or at least the cans in the UK where they filmed this the narrators state that the coke cans are made of aluminum but the pepsi cans are made of steel.  The main purpose of the experiment is to display the properties of aluminum and how it reacts with acid as well as a base.  Just a reminder on the ph scale a 7 is neutral like water and anything higher than that is basic.  Anything lower than 7 would be an acid:

0 1 2 3 4 5 6 (7 neutral) 8 9 10 11 12 13 14

Apparently the basic is just having its way with the coke can.  The acid not as much and this was to the surprise.

Gross whats left is the plastic left from the can.

The pepsi cans although did not participate in the experiment because they ar emade of steel likely would have held up much better than their bretheren.