I've been wanting to add something like this for a little while, but I had some trouble figuring out how to integrate it with a map. (should states be a different color if there's a pending action? Or should they...um, blink, or something?) You can see I've solved this Gordian knot by cutting through it, as it's not tied in to the map at all - it doesn't even go "back in time" with the rest of the map. I think this is about 95% good enough, since this keeps the current pending actions at the top always, and really, who cares about pending actions in the past that aren't pending anymore? (not to mention it would be a lot of work to add that data...)
Luckily the data file is flexible enough that I was able to add those entries without breaking the TouchPad or Windows Phone clients. Someday I'll go back and update them to include this info.
Suggestions, as always, are welcome. (like a less dorky name for "pending actions", for example...)