Hi Les,
Yes, there are ways to do this in a map series. It all depends on what kind text you are working with (layer labels, annotation feature class, or graphic text (map), or graphic text (layout) and the type of map series (spatial or bookmark). Bookmark map series do not support page-driven dynamic text.
If the text are graphic (either inserted in the map view or inserted in the layout view) you will not be able to make these dynamic. Graphic text is currently static and will not change. If the text is an attribute of the map series index layer you can use a Map Series dynamic text element (inserted on the layout). This will change based on the visible page.
If the text is from an annotation layer you might be able to use a page query to specify which annotation text draw - provided that the annotation has field/values that match the index layer driving the map series.
Hope this helps,
Tom
