I know some people will be outraged from reading the title, but there is a possibility that Ironhide might switch his side from being an autobot to decepticon. The reason being is that he wants to get rid of everything that looks like a pest to him. For Example, Sammy, the chihuahua that lubricated him, Sammy's parents, and almost every human he talks to. Of course, Optimus Prime is not happy with Ironhide's attitude toward them and this relationship might cause Ironhide to betray his side and join the decepticons.
And if this really did come true, then Ironhide might steal the remnant of the AllSpark so the Decepticons can use it to bring new life to Megatron.
Ironhide "You wanna piece of me punk?"