No. We sailed Medit. on 3 different ships (including Legend and Splendor) and the ships' electrical system in cabins is U.S. However, if you have a pre- or post- stay in Barcelona (or where ever), be sure to take a converter.
We stayed at St. Moritz last year and I had the presence of mind to bring along a converter (always carry with me whenever we travel in Europe). I find it easier than taking dual current appliances (hair driers, curling irongs, etc.)
I envy you! We plan to cruise the Medit. again next May on the Millie. Wish I was going again this spring!