After playing CTF quite a bit for the last few weeks (my favorite mode) I find that I spend a bit of time doing dumb things that are based on my faulty understanding of where the flag is. For example, I'll get the opposing teams flag only to discover that my flag is gone. Likewise when trying to get the enemy flag. I may guard one of the exits of my building in response to the "The enemy got your flag! Retrieve it!" message in hopes of intercepting the person leaving with my flag only to discover that my flag had been dropped somewhere else, and was just picked up.
I realize that there are text messages for all of this, but they seem to be easy to miss. What if there was a visual indicator, just like with the amount of ammunition and health? How about if it looked something like these two examples:
1) The blue team is in possession of the red flag and the blue flag is at its base:
2) The red flag is at its base and the blue flag has been dropped somewhere:
I might be willing to take a shot at implementing it if there is enough interest. The examples above were just done in the gimp (they aren't screenshots).