Imagine this, you are getting sniped a lot and you are just tired of it. So you bring in a 155mm howitzer and launch a shell into the window and you destroy those snipers and proceed.
Like this: http://www.youtube.com/watch?v=uoZ1900AhDU
How is this useful you might ask? Snipers can be overpowered especially in groups. Howitzer can balance that out. The howitzer can take out the sniper and destroy the base. The howitzer has 4 shells and a long loading time. So its not automatic which leaves you partially vulnerable. Since this is such a big gun and too many of them can cause some issues the server owner will have the choice of limiting how many howitzers 1 team can have. After the howitzer fires its last round it breaks, then the team isn't allowed to place a new one for 2 minutes(Prevents over usage). The howitzer can shoot from up to 350 blocks away. It is placed the same way the new machine gun can be placed. If the howitzer is shot 5 times with a rifle, 10 times from an SMG or 3 full loads from a shotgun, it will break. Using a spade you can smash the howitzer with 18 hits. The howitzer is very large, about 3x3x3 blocks in size. Since the foundation is 9 blocks, and it takes 2 hits from the spade to break 1 block, it would take 18 hits to break the howitzer. The round it fires is grenade sized and once it hits the ground it creates an explosion as big or maybe bigger than a grenade.
Wouldn't it be awesome to have a cannon in the game> something a bit more fun the plain old guns?