Yes, they appear in towns, probably much like Deckard Cain worked in Diablo 2.
In addition, I believe Jay mentioned that each player will just see his own Artisans. If you want to make use of a friends artisan, they implied you could hand them the resources and they could have the item made for you. At least this was the system they currently had in place. As an example, the stash in Diablo 2 worked this way. There was one stash in town, each player saw his own stash when he used it.
Although, as always, this is subject to change. Jay acknowledged the fact that they know players want to "show off" their artisans. But it may just take the form of "yes, I have a lvl 5 blacksmith, need anything?" type of situation.
[ Post edited by T3mplar777 ]
"Sometimes I do what I want to do. The rest of the time, I do what I have to." - Cicero, Gladiator (2000)