That statement is nothing special, both Markdown and asciidoc claim to be a formalisation of the plain text conventions you already use. IMHO most of the alternatives mentioned in this comment thread understand their goals and the design space well enough, and many are definitive improvements over Creole's MediaWiki-inspired, committee-designed syntax. They also win in featurefulness (Markdown and Textile have html embedding, asciidoc and ReST have extension mechanisms), which is important for a wiki.