If they significantly change concentration spells and even the concentration mechanic. I don't like how it is a Con roll; I can't tell you how many times my monster's spells are ruined goddamned immediately because they can't maintain it after getting wailed on. I prefer a Concentration skill so you can get better at it. Also, they would need to address bonus actions. If they juggle that stuff around I would be inclined to purchase the new edition. If they don't, and it is mostly light fluff alterations, I won't be. So it is far too early to tell.