You can use all wiki markup for making your slides - just keep the following in mind:
for a DiaShow, a bigger font will be used, so don't put too much on a slide or you will have to scroll
- if you use colours, keep contrast in mind - especially if you want to make a printout.
- presentation will look different on the beamer and on paper as on your screen.
- if you use graphics, use thicker line width or they will be hardly visible.