YouTube is setting up shop in Turkey, with a brand new and local domain name and a company set up in the country. Considering that YouTube has been blocked in the country for a long time and that Turkey is one of the fastest growing internet markets around, Google's move makes sense.
Users in the country will be redirected to the local youtube.com.tr domain and content will be localized, but other than that the experience should be fairly similar.
But it does come with several disadvantages, having a legal presence in the country means that, for one, it has to pay taxes for any revenue it makes there, but also that it can be held responsible by local courts.
Until now, any legal issues settled by a court meant blocking the site altogether since there wasn't much else a court could do. Now it can issue an order for the local YouTube which it has to obey.