Up till recently on amazon.ca the Add to Wishlist button would always add to your default list. If you wanted the item in a different wish list you then had to move it with a second step.
Now they've made the obvious improvement, you can pick which list to add the item to right from the start, avoiding the second step.
Buttons with pull down options are becoming quite common. I think they're a good way to handle this kind of thing.
Of course, I'm never satisfied! Next I'd like to be able to add to wish lists directly from the search results rather than having to go to the items page first.