
I've just released the new Lightroom Plugin that I've been working on for the last few weeks:
Jeffrey’s “Folder Status” Lightroom Plugin
It lets you create per-folder metadata flags that track personal workflow milestones as you work with images in a folder (for example, “Keywording Done”, “Off-Site Backup Saved”, “Geoencoded”, etc... whatever you want), and through export-prerequisite rules based on these flags, to help ensure that you don't accidentally export photos from folders that haven't yet received at least whatever minimal processing you think is important.
How you work with it depends greatly on how you set it up and what kind of things you want it to help you with, but to illustrate, here's how it can look within my personal setup:

Full docs over on the new plugin's home page.
A truly workflow enhancing plugin! Thanks for all the excellent work you do on all your plugins!