No, Wedding Gift should be something memorable and I dont think it is good to give it as a wedding gift as it is only a money after all, which no one will not even remember after it is spend away. Wedding Gift should be something special and useful for our lover.
It would be better if we say that the number of people who are aware of bitcoins in advanced countries is different from those who come under other two categories (developing and third world countries). So if someone lives in Germany, he can give bitcoins in gift to the new couple and they will admire it. However, the idea itself is an outstanding one.