Carrier pre-orders are beginning to arrive on door steps. In fact if you ordered your Galaxy S8 or S8+ from Verizon or T-Mobile you more than likely already have your phone. If you were waiting on the unlocked version to become available you can pre-order that now. The unlocked version won't have all the carrier bloat that you would get with the phone otherwise. You will also be able to take it out of the country for use on GSM networks, and will be able to easily change between networks at home. The one major set back to going this route is speed of updates. Samsung is notorious for saving unlocked models for last when it comes to updates. I have spoken with some unlocked S7E users who have still not received the update to Nougat which is just mind boggling. If updates aren't important to you and you need an unlocked phone you can hit up the link below to pre-order.
via B&HPhoto