*Chuckle*
I'm actually leaning toward the Skaven reasoning. The Warhammer World has become a little too happy-go-lucky for my tastes. As a player (not as a General), I'd like to see the Empire break into a bit more fragmented society. I was going to post this earlier, but I'll reply now...some thoughts for discussion on Week 6.
Premise 1: Dwarves are stubborn, unrelenting, and downright tenacious. They won't leave without what they came for.
Premise 2: The Dwarves are and consistently will be ranked very high for the rest of the campaign.
Premise 3: Karl Franz wants the Crown, approaching the point of obsession (or at least he has up to this point).
Premise 4: Come Week 6, "the end of campaign season," the Dwarves will begin a withdraw to their Holds.
Conclusion (that Karl-Franz jumps to): "Thorgrim won't leave without the Crown...but he's leaving. But he hasn't told us that he has the Crown...THORGRIM MUST BE TAKING THE CROWN TO HIDE IT."
This would be a coordinated Week 6 all-out Fluff offensive regarding a breaking of our treaties. The Asur, Brettonians, Dwarves, and Skaven would all be involved (in advance)...the more races we could work in, the better.
The overall premise: Karl Franz orders all Imperial officers to concentrate their attacks upon the Dwarves (with no warning to them) and to take back the Crown, wherever it is (which the Dwarves probably don't have, but we disregard their denial as "lies"). The Asur (of course) aid the Dwarves, their allies; the Skaven jump at the chance to kill Dwarvenkind. The Brettonians, with alliances to both, are stuck in a moral quagmire.
I know that this violates our pre-campaign treaties; we would discuss this with those parties beforehand (ie, soon). This also, I know, goes against many of our loyal Imperial officers' morals. Many good men, thus, disregard orders; some choose to continue their operations from before, others openly fight on the side of the dwarves. Many other loyal officers, placing Empire above alien races, conduct their operations despite their own consciences. The Empire threatens to tear apart...
Personally, I think it's a great plot hook for GW's future. The Empire's been lovey-dovey and happy and glorious for long enough; let's see a twist for the worst. Give the VC a real chance at becoming a threat again; let's see a major city sacked, and the Empire disregarding the threat of Chaos (after all, their beaten and broken...right?) and at each others' throats instead. More importantly, GW's been very compliant with the fluff that has been submitted up to this point. If at least five races - maybe more - are suddenly contributing to this, they may accept it. We may have a chance to have a real say in where the Warhammer World goes from here. Years from now, when our kids are playing Warhammer, we can talk back about the "golden age" of the Empire, when everybody got along, and how we were part of the campaign that had the first big effect on the world.
Storm of Chaos proved that the powers of evil can't break the Alliance of Light. It takes infighting to do that. I'm all for it. Mind you, that's as a Warhammer enthusiast in general, not an Empire player. As an Empire player, I'd love to see the Empire conquer all the known world...but that ain't happening. But there's precedent for Civil War. It's not beyond the scope of the game or the storyline. It's something we can make real. I think that's the most appealing part of it.
Anyway, that's all up for discussion. But now it's out in the open. If we're going to do something with it, let's do it soon. Otherwise, this will just be another forgettable summer campaign conducted over some cheesy made-up artifact that will just conveniently disappear immediately after the summer, and nothing will really happen. I want this summer to be different...