What if instead of having to take the intel in the enemy base, you have to take something from your base (let's say a bomb), and drop it in the enemy base.
Of course the position of the bomb carrier need to be shown of the map.
(there a debate about it here: http://ace-spades.com/forums/topic.php?id=225)

Before saying anything stupid like "AoS is not CS!" think about it.

With this idea, each team can have a real sense of progressing as they get the bomb closer and closer to the enemy base.
It will create natural chokepoints where most of the fight take place.

And the difficulty of scoring a point will be more balanced: Now the hard part of capturing the intel is getting into the enemy base, because the intel is usually well defended.
Then, when you have it, it's almost a peace of cake to get away with it, because having the intel often means that you have killed all the defenders first.

With a bomb, it will be harder and harder to advance as you get near the enemy base, it's more logical.

When the bomb is planted, it can even blow up for real. For once in a video game, planting the bomb will be really useful because it will destroy all the enemy defence for the next time.

Then you can add more things to spice it a little, like multiple objectives to destroy and things like that.