Note that this is a hybrid slot the second card can be either a nanoSIM or a microSD, but you cant both expand storage and add a second phone line.
In Germany, it will cost you 900 and is available in Midnight Black and Orchid Grey. You get a free wireless charging station (valued at 80) to offset some of the premium. Its the same price in Austria, though without the wireless charger. In Spain, its 910 and, again, no charger. Thats still better than Italians, who have to pay 950!
Those are all the EU stores we confirmed are offering the Galaxy S8+ Dual SIM, but others could join soon. The smaller S8 didnt get a dual-SIM version.