While developing wireframes and design comps, you never include actual text, or “copy” as it is referred to. The writers assigned to a web project typically generate copy in Microsoft Word documents. The copy gets folded into the web site only after it has been revised, proofed, and approved. The copy usually goes right into a database bypassing the visual comps altogether.
Trying to refine and edit copy in graphics software tools during the design process is not an efficient practice. Not only are designers usually not also the writers, but you do not want the visual creative process hampered by attempts to come up with pithy headlines and informative body copy. So, what designers do is use fake text referred to (wrongly – it’s Latin!) as “Greek text” as placeholder for body copy in their comps.
Designers will use real copy for navigation elements and main headlines so that team members and clients can better evaluate the page design, but it must be made clear that this text is not final and only there for visualization purposes.
See how above that shows a mix of legible headlines and placeholder Greek text. A great online resource for generating Greek text can be found at http://www.lipsum.com/