So you are looking for an autoupgrade kind of deal? Here is an option for you although it is not exactly what you are looking for, take another whole CD copy it to your HD then delete what is not needed via the slimming batch's mentioned above, then copy both distros to the iso, WXPP and WXPU, create your ISO with cdimage using the -o switch to optomize, this way you have the option to run Gosh's method of a clean format and then you have your upgrade method. This will cause the minimum amount of data neeed on the CD.