I think PowerPoint already does this; Keynote's had it for ages, and I've done it on Linux with Beamer a few years back. You have presenter's notes with a small

I think PowerPoint already does this; Keynote's had it for ages, and I've done it on Linux with Beamer a few years back. You have presenter's notes with a small slide preview on the screen in front of you, actual slides on the big screen. These days I run my presentations in reveal.js (HTML5), so the output is trivially cross-platform and videos, 3D content etc. always work flawlessly. This also has speaker notes, implemented as two browser windows (one for each screen) with linked controls.