LaTex, being a markup language, can easily be converted to other markup languages, such as HTML. All you need is the latex2html perl script (via CPAN) or Hevea or Tex4ht (both via Fink). You can run these by hand from the terminal or AFAIK you can make a macro/script to use directly from TeXShop (see TeXShop docs on how to write your own macros).
To make slides with dynamic effects (moving text etc.) or otehr kinds of static overhead foils/transparants you can check out packages like ifmslide, pdfslide, texpower and/or ppower4, all available through Fink.
Again, this is not the intended use for (La)TeX, so YMMV. It's not all that easy, if you are new to LaTeX just start by making simple documents with the default layout. If you want to play with advanced options, by all means, try them out, but do not expect fantastic results from your first trials.
What exactly do you mean by wiki output? The content of Wiki's is just plain text with special markup for the links and limited use of other basic markup. You can surely write a (perl)script to convert LaTeX to something like that. If you want to generate the entire (X)HTML code underlying a wiki webpage, that's obviously impossible, as wiki's are based on PHP and MySQL.