I don't think it will be that bad. WebKit is already pretty well established, when they're this far along I doubt they'll diverge much. For the most part, even

I don't think it will be that bad. WebKit is already pretty well established, when they're this far along I doubt they'll diverge much. For the most part, even Firefox and WebKit render the same, even though they have no common lineage. This isn't going to be like IE6 vs Firefox.