An idea for a new mode (That'll never happen, of course)
TF2 is a game with plenty to do: CTI, KOTH, Payload, etc etc.
But you know what would be a great idea to add to TF2 that could change the way we play? An objective mode.
Think of a mode where Teamwork is more important than ever, unlike all the old modes. In most of the modes the game has, you don't see too much teamwork. But in Objective mode, it would make people work more as a team to complete objectives. Red would be in charge of keeping Blu from completing a number of objectives such as:
1: Wall demolition, where demomen are needed to set up a bomb to blow a path to the next objective.
2: Sap (objective), where a spy needs to sap a really important gizmo and keep the sapper running until it fully drains the objective.
3: Build a certain structure or repair something with engineers, which take a lot longer to build than a normal sentry, but are just as important if you want to finish the mission.
Of course, those are just a few ideas for objectives. With the number of classes in the game, it would allow for all kinds of objective ideas to challege the Blues and Reds, as well as encourage teamwork in a fun way.
Of course, I doubt it'll ever happen. And even if it did, it would take awhile before it ever became a reality, due to all the work it'll take to make big maps and all the fancy objectives within them, lots of testing and whatnot. But still, a guy can dream.