Exported PowerPoint / Keynote files do not include notes. There are a few workarounds, however, that will help in a pinch:
1. You can copy and paste your notes from private notes into public notes. That way, the notes will accompany your slides online, and you can share the deck URL for others to view your deck with its notes.
2. You can play your deck on your iPad, and rotate the iPad so that your private notes show at the bottom, then screenshot each slide. To screenshot, press both the sleep/wake and the home (round plastic) buttons simultaneously. This saves an image to your camera roll of everything on the screen. You could do this with each of your slides, then email the images from your camera roll.
3. You can export to PDF, which will include your public notes.