Winapt version 0.5 is also Winapt RC1. Let me know what you think. Winapt RC1 does not require wget or gzip, and has a -q option (quiet) and a -l option (list installed programs).
Documentation for Winapt certainly isn't "complete," but there is now enough of it to keep you busy for a while. There's a Wiki, FAQ, Manual, Strategy Overview, and various pages about data files and algorithms/logic.
While still in beta, the Winapt 0.4 (released August 6, 2008) is a stable application. I still have features to add, input sanitizing, and of course, the list of packages is still rather small; however, it does what it's supposed to do, and it is highly unlikely that the format for the package lists will change.
Finally, an apt tool for Windows. While this is now in the very early stages, it is usable. For a list of applications, please go here: