Looking through my expired IDs, I noticed there were distinct categories:
1) Stuff that is dead and done with.
2) Stuff that turned into something else
3) Stuff that is actually under current development but hasn't made an update in the past 6 months because I have other stuff ahead of it.
It would actually be very useful to be able to distinguish between these cases. Especially to distinguish cases 1 and 2. For example, a lot of times a WG will ask for comments to be submitted as an ID. The WG has a discussion and the issue is closed. In such cases no successor document is likely to exist or be created in the future.
In other cases though, I have drafts that I have stopped working on because I have agreed to merge my proposal with someone else's or the draft has become a WG draft but in a non-obvious fashion.
It would be really useful to be able to track these so that when I am looking at past proposals, I can see which have died because they were no longer needed and which I should probably be doing something with.