1) Does this strengthen the divide or weaken it? Holding the AV referendum on the same day as local and regional elections was always on the cards: it's the best way to ensure a relatively high turnout, and it smoothes the logistics of it all. But you wonder how it will play within the heat of an election battle, with Lib Dems and Tories gunning for each other anyway. Will Tory resistance to AV make the the divide between the two more pronounced and poisonous? Or will the very fact of the vote placate the Lib Dems, and ease any underlying tensions?
2) Would this compensate for a poor Lib Dem performance? One of the biggest worries in Coalition Land is that the Lib Dem's downwards trend in the polls will be reflected in election results next year. At that point, all kinds of difficult questions could arise about what the Lib Dems are getting from their link-up with the Tories, and even about the leadership of Nick Clegg. A win in the AV referendum could nullify some of that anger. But a defeat could send it spinning into overdrive.
3) What would Labour do? David Miliband has already been on the airwaves this morning, saying that he would support a 'yes' vote in any AV referendum. Given how this was a Labour manifesto pledge, there's a strong chance that the majority of his colleagues would want to do similar. Which certainly throws up the potential for cross-party mischief. We could, perhaps, get a situation where the Tories are campaigning against a joint Labour and Lib Dem "progressive alternative," so to speak. And you can bet that the Lib Dem left would relish that.
All in all, the referendum is shaped to be one of the most significant moments in the life of the coalition. And now the countdown has well and truly begun.