Elizabeth Smith has a new post today points out some Windows builds of some of the more popular PHP-GTK2 widgets she's compiled (including GtkSourceview, GtkHtml, and LibGlade).
I have these extensions building on windows, or have found someone else who is building them for windows. You can find downloads that are either the full distributions (if no one else is building them) and/or the runtimes + items needed to build with PHP-GTK2 at my callicore build site with the other gtk libraries.
She uses the rest of the post getting into some detail on how she compiled the modules, issues she had with some, and what widgets/packages are on the horizon.