It appears to me that all references to controls, forms, graphics, printers, and dialogs need to have "Vcl." added to them for XE3. I have tried that, but still get an error, just a different one.
[MSBuild Error] "C:\Users\Public\Documents\RAD Studio\10.0\BPL;\stuff.bpl" is an invalid value for the "OutputFile" parameter of the "DependencyCheck" task. Multiple items cannot be passed into a parameter of type "Microsoft.Build.Framework.ITaskItem". Where stuff is the new package name I was trying to use.
Bill