The Han's shirtthing was discussed on MF.com recently. Apparently it was never an error at all, just really dark shadows. Whether the vest was or was not fixed is moot. The real problem lies in the fact that he is wearing a different shirt when he's thawed in RotJ, and the arm binders are gone. i somehow doubt Jabba decided to thaw him briefly to let him change his clothes.
As for the fixing of the uniforms, does this mean they are actually thinking while making some of these changes? This is an actual worthwhile change, the type that I welcome.