I know of and have tried out org-present and org-tree-slide. However, neither really gives me everything I want. I almost always need lots of nice math type-setting, which is why beamer has been my go to since forever. Plus, I don't see an easy way to get step-by-step showing of content a la overlay in beamer or fragment in reveal.js. That's something I must have as it is central to my presentation style.
However, I do agree that for extremely simple, quick and dirty presentations, nothing can come close to org-present/org-tree-slide, at least for #emacs folks.
Wrt executing source blocks, there are options like pweave (and an r equivalent) for beamer/latex. For reveal.js I think klipse plugin allows execution (albeit of a small selection of languages, with others needing custom work).
Most of the time, I don't need to execute code live, at most I want to be able to show relevant output based on parameters set earlier in the presentation (for which weaving/klipse are sufficient). Also, editing typos is not an important enough feature for me to switch.
Thanks for the discussion though. It is important to know use cases where one tool is superior to another. If I ever teach a programming heavy course, I'll probably use org-tree-slide.
