It would be nice to be able to save a draft of longer texts.
WordPress does auto-saving, which is a nice feature. I think it fires every ten minutes, and I know it keeps the drafts forever, since they are generally incredibly small compared to most hosting space.
It saves the draft regardless of the post length. This might be useful for someone who is posting something a small message, and has to step away momentarily; then it doesn't have to check length, which may be a little easier ne?