I deal with a lot of people delivering presentations in my day job. The defacto standard is MS Powerpoint. Powerpoint has a lot of problems, and is lagging behind in features when compared to some other presentation software. This Idea lists these problems and missing features, looks at other software that tries to bridge the gap, and I offer some of my own thoughts on extending some of these.

Powerpoint's problems

• Doesn't cross platforms well: Authoring Powerpoints is somewhat cross-platform: you can create with Office on OS X or Windows, and (Open|Libre)Office on pretty much every OS. AFAIK, there's no way to author on phones or tablets. However, I see lots of layout issues with (viz.) Mac Office to Windows Office, due to a lot of reasons mostly having to do with adding non-PPT content via linking or embedding[1], but I've also seen unexplainable things like arrows drawn with the drawing tools moving around.
• Requires software that is not available everywhere (FLOSS OSes, UNIXen, and phone OSes).

Powerpoint's deficiencies

• Zoom-based transitions: Prezi, a Flash-based presentation format (sadly), counts zooming as one of its primary selling features. I think zooming is a very powerful way of relaying information, because it intuitively ties the informational detail level with height of the view point, like a mind map without lines.

Existing tech

• w3c's HTML Slidy, might be a precursor to or subset of S5[2]?
• s5, another XHTML-based presentation standard