It would be useful to have the ability to sync the wishlist with an online accessible site. I'm not sure if sites like DeckBox or TappedOut have any API's that would make this possible.

Another (probably easier to implement) option could be to allow exporting and importing of the wish list specifically that could then be used to put it into a site or back to the device.

As far as I know, there aren't any APIs which would make this possible. You can export the wishlist by sharing it from the menu, but there is currently no way to import one. We're going to stick with manual entry for now.