I work as a web designer for a medium-to-large SaaS corporation, and spend a lot of time looking for best practices and solid ideas for our corporate website.
I would argue that very few corporate websites use a width: 100%. Most have a max-width set, though a lot of new corporate websites are becoming responsive.
Here are three solid examples of what I consider to be corporate websites (though most of them are selling their products right from the homepage):
As you can see, all of these have a max-width set somewhere. Most corporate websites I've seen incorporate some sort of max-width.
Here's a few trends that extend throughout these three sites, but also a lot of new corporate designs:
- Solid, bold colors within different sections and blocks. Using white as a main background color is becoming less and less common--bring in your brand colors using strong, big colored blocks.
- Less use of shadows and gradients to create depth. They're still used very predominately in CTA's, however.
- Grid layout structure
- Fully responsive design (try sizing down your browser)
- More photography, graphics, illustrations, etc. are making their way into corporate site design. However, all these design elements feel very in-line with the brand and are likely established by a brand guide that defines these styles through all their print and web media.
I would concentrate less on determining a width of a site, which is largely determined by the content you're trying to support, and focus on picking up on some of these other trends.
Most of these trends for corporate site design work well with a grid-like, fully responsive layout that has a max-width. Most seem to have a max-width over 960px (most seem around 1000-1200px).