Will we ever have another continent wide conflict like this one? (this large)
As things currently stand, not unless it's possible for the CE bloc to fracture from within and go to war with itself. Thus your perception of whether something like this could ever happen again depends first on your answer to that question, and after that on unforeseen and inherently unpredictable circumstances that somehow change the status quo and significantly weaken the bloc, like a secession or a mass exodus of players.
Logistically speaking, all credible resistance to the Empire will be broken after this conflict. Outside of the realms that are solidly in the bloc, who would fight the Empire after this? The North will be fractured and weak; without Darka and Eston, there will be no Great Powers in the North. I expect both realms will survive in some fashion, but much reduced in power and influence. In the South, Suville is too weak-willed and distracted by conflicts with its neighbors (disclaimer: so far as I am aware), and besides that they were a very long way from realizing their potential as a Great Power when I was briefly there. Tara alone could have steamrolled what passed for their army with little trouble.
Basically there are only two Great Powers left on Atamara (or rather, that is shortly to be the case), and those are CE and Tara. Barring the aforementioned unforeseen circumstances or them turning on each other, it looks like we're soon to enter a period of prolonged Pax Cagilis with nothing but one-sided gang-bang wars in the future.