I just realized that the Debian Installer is ten years old! It actually got started ten years ago last summer, but now is also an apt anniversary -- ten years ago, I successfully booted d-i for the first time.
It's amazing that d-i has been around as long as Debian Developers who have "been with the project longer than most". (Many of whom have been long-time contributors to d-i themselves.) Astonishing that my basic design has held up and remains relevant. And every time I boot up the Debian kFreeBSD installer, or run the graphical installer, or hear someone raving about how easy Ubuntu was for them to install (and know d-i was underneath), I'm amazed at the places people have taken d-i.
The code has recently moved to git. As changes like ext4 by default start to flow in to d-i, with Wheezy development starting up, I hope to see more people enticed into working on d-i.
Anyone can do like Matthew Palmer has done with netcfg -- pick a component of d-i that interests you, check out its git repository, and take it from being reasonably well team-maintained to awesomely you-maintained. In five or ten years Matthew will be able to look back at all the people who have used d-i to install over IPv6, and on WPA wireless, and with his other netcfg improvements. Trust me, it's a great feeling.
Previously: d-i retrospective (better written than the above & well worth a re-read)