Troop Upgrade: Level Seven Balloons
Supercell should create a troop upgrade to balloons for Town Hall 10 or higher. The balloon would transform from a single hot-air balloon into a blimp with the addition of an extra skeleton. The fire rate of the balloon would double, although the damage per second would not increase significantly, meaning that each drop from the skeletons would do less damage. The overall statistics of the troop would increase, but slightly.
The appearances would change somewhat drastically, as the balloon's length would increase, and the basket carrying both skeletons would also have to change size. The bomb dropped from the level seven blimp could be much like that of the wallbreaker's level 6 barrel. The color of the blimp could stay about the same with the skull graphic printed on the side, while the armor protecting the fabric on the balloon could have and addition of spikes.
All in all I think this troop would be a fun new addition to Town Hall ten or higher attacking. With the addition of a more powerful upgrade, new defenses could also be implemented.
Let me know what you think of my idea on upgrading balloons to level seven in the comments. ;)