So there is no real urgency to replace our nearly 50-year-old M-109 design. The FCS program replacement was killed:
The U.S. Army appears to have lost its second replacement vehicle for the half-century old M-109 self-propelled 155mm howitzer. The new XM1203 NLOS-C self-propelled 155mm howitzer has been, well, if not cancelled, then suspended.
The king of battle, the cannon, isn't getting a lot of respect. I don't miss the Crusader--it was ridiculously heavy. But the XM1203 seemed to be a good next step. But apparently not.
So we'll make do:
In the current war on terror, even the M-109 has not been used much. The lighter, towed, M777 has proved more useful, especially when using the Excalibur shell. Currently, the army plans to keep M109s around until 2050, just in case. You never know, and it pays to be careful. Meanwhile, the army is planning to make a third attempt at a M-109 replacement. This will also borrow from Crusader and NLOS-C, and might even succeed. Eventually.
If we ever face another large army on the battlefield with an air force that can at least run interference against our air supremacy, we'll miss having a decent sized artillery force.