I have looked into it, and might snipe a few ideas. If you have some time over check out www.morphix.org, the 0.3 version has the GTK2 installer (try out light, it's an easy download )

However, i must sniffle the rumor that PGI would be included as the default installer. You are right that a lot of work is being done on the default debian-installer, but this is not PGI! PGI might be a nice alternative, but Debian is all about supporting multiple platforms. That, and that there still are people installing over a serial link