I guess I'm in the minority that would love to see a new edition. Granted, it wouldn't be around for another three years, but actually, when you think about it, after another three years of fifth edition supplements I think most people would be ready for a change.
We've had some great books this edition and we're blessed with some great talent contributing to the line (I do what I can too), but I can see that I'll be looking for the game to move forward before long. And if there's a three-year turn around, then I don't want to wait three years before we start putting it together.
What would change? Plenty. More than enough to justify a new edition. And not just the rules. There's room to play with the Houses still, and there's room to play with the Order as a whole and the Code and its peripheral rulings. All in the name of looking for the play opportunities and presenting them up front. We're almost up to the point of having completed all the Tribunals (across three editions, granted), so we're almost at the point of rewriting them in order to bring them up to the latest edition. Why not do that with a new edition?
And there are enough rules that look to be in need of attention to justify a shift. What happens if you get rid of the XP distinction between Art and Ability? Do you adjust some study source qualities to address that? Can we rework PeVi to make trapping a demon easier (and therefore a sensible option) than destroying it outright? Can we make Parma Magica a little less of a freebie and more an active part of play? Can Certamen ever reach its potential? Can we clarify Craft vs. Profession once and for all? Can we make the Verditius the craftsmen of the Order that they're supposed to be?
It's tough because the basis of the fifth edition is so bloody solid. I look across at Faerie and I dread changing it. I look across at books like Art & Academe, City & Guild, and Lords of Men and you get everything you need to play across academics, merchants, and the nobility. It's a great line of books, to say nothing of what's out there for the Tribunals, Houses, and extensions to core magic.
But the rules are, for my money, starting to creak under the weight of books. As a community, we have a sense of what works and what doesn't. But I don't think those things can necessarily be addressed individually. If you want to solve the pink dot problem, you're going to have to look at Resistance and Penetration. And if you look at those you need to look at Parma and/or Might and spell-casting. If you don't want wards to penetrate, we have to ask whether that's really what you mean... or do you mean it should be easier than plastering the critter across the wall with the same level spell? And if that's really what you mean, then how much easier should it be and why? These things need to be consistent and logical and I don't (so far) think that's achievable through making a list of exceptions to general rules. And while I think a public "swap shop" of ideas is grand, I wouldn't dream of using them in my game. Not to slight anyone, but it's hard enough keeping twenty-odd books straight let alone a hundred wiki pages too.
I respect David Chart's stated position that fifth edition is his vision for the game and that he might find it difficult to undertake a sixth edition without finding an equally strong but differentiated vision. My hope is that he can find way of looking at the Ars Magica universe. Different enough to justify the investment of time and energy in bringing the game on into another edition.