Note 11: You have to close and reopen the project in the IDE to enable themes at design time.
That is, as you use the "Enable Themes" project option. Having themes enabled in the VCL designer (and a couple of themes-related bugs fixed) is one of the Delphi 2007 features I appreciate most. This blog post is part of my "113 Delphi 2007 Handbook Notes" blogging project, to promote my new Delphi book. BTW, this was posted while at the Malpensa airport, near Milan.