At first glance there doesn't look like a way to save your slideshows into a format that you can send to some one. If you look a little further you'll see you can indeed export them though. It exports the whole slideshow into a PDF Presentation (much like Photoshop's PDF presentation automation). However, it won't include any music tracks you've added in Lightroom. Well there's a workaround if you've got Acrobat Professional. You can go in after the fact and embed the music to the presentation and get close to the same effect.