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.
Start your career in Graphic Design with the WonderHowTo's Beginners’s Guide to Photoshop Course