Markup isn't really a big deal. There's only so many ways to markup certain kinds of features anyway. This only really starts being an issue is when your site l

Markup isn't really a big deal. There's only so many ways to markup certain kinds of features anyway. This only really starts being an issue is when your site looks substantially similar to another site. That's more to do with CSS, colors, imagery, and content. It's actually quite easy in many cases to visually replicate a site without using the original HTML at all. I wouldn't worry about it.