>Suggestions and Feature Requests>Target calendar
Roads were made for journeys...
I dunno. Not that it doesn't sound cool, but I've seen too many websites where the amount of features diminishes user-friendliness. I think one of the great things about RA is its intuitive nature and relatively simple interface ... Adding more gray boxes to the calendar windows, another calendar on top, creating comparison features to show planned vs. actual, separate graphing....it all sounds a little clutterish. Maybe it's just not a feature for me, but I fear superfluous option boxes would push the site a little too far over the "technical" side.
Another way I've seen it done is to create a run type called "Planned Run" (or in your case, "Target Run") by using Options --> Workout Types --> Running and then filling in "Target Run" in one of the blank boxes. (You can change the colors of your bars here, too, by the way!) Then, you would enter in your target run data, using future dates. (You can do this!) The only problem with doing it this way is that your statistics will get all messed up unless you detlete your "Target" runs as you go along (or "edit" them and change the run type to easy/hill/whatever and fix the actual time/distances). It also changes your stats for weekly miles, so if you're in a pace bunny group this won't work for you.