I think we in these forums are dying to get one. We are on the bleeding edge.
There will not be lines forming.
I think there is enough people who have been waiting for an Apple watch that there will be lines. As a percentage of the overall population, we may not be that many, but it's easy to imagine, for example, in New York city,, at least several hundred people showing up at each store. That will create lines.
I think if there are no preorders, I'll probably get up very early, like 5am, and get to the store around 6-6:30 to stand in line.