http://forums.spiralknights.com/en/node/44920#comment-296613
Going on almost 10 months now and this still hasn't happened. I've made numerous posts asking about it, and we still get any kind of update? I don't find this acceptable as a customer to be told about a feature update and having to wait for so long with very little coming from development on how this is going.
What was the complication that Nick mentioned regarding the Iron Slug buff/reimplementation?
Basically, the tools don't currently exist in the game engine to do exactly what he wants. The original implementation was done with the tools that were available, and were not getting the results that Nick wanted. So it all comes back to getting the time to implement the new features that would be needed to do the desired implementation.
From the clockwork confidentails interview with Curio, one of the engineers for Three Rings.