My supervisor's supervisor told me that the work I did has laid the groundwork for the team's primary push for the next six months, and I had it much more complete and ready much sooner than they expected. Specifications documents I wrote will become direct policy for over 275 people. My supervisor's supervisor's supervisor told me that I am exactly what he is looking for in an employee and he wants to hire me... and he is the man who makes the final decision on hiring.
I finished my project. I'll miss the people, but I don't feel like I've left things incomplete- things are at a logical stopping point for the next people to pick them up.
The door shut behind me, but I don't think the end of this internship was really the last anything... I proved that I can do a very effective job working and living in almost the real world, and I'd say I'm ready. I'm going to graduate college first, of course, but I know now that I'm really ready and I can really do this- and every indication is that I've got a job all lined up, too.