You didn’t do anything wrong, the libraries haven’t been updated to be compatible with 1.0 yet. You can take a stab at converting the library yourself, and I might take a look at it also.
Please reference this thread. The third post outlines all that should be necessary to modify the library.
Update:
I downloaded the lib. All you need to do is change “#include <WProgram.h>” in DualVNH5019MotorShield.h to "#include <Arduino.h>"
It compiles the demo fine with that change, and should work fine overall. However, I do not have the hardware to actually test it.