A seamless integration of a WordPress blog into your existing site structure would entirely negate the need for PowerCMS.
I can't now envisage creating a site without blog integration (whether or not the actual blog pages are public) - there are huge advantages, - content can be drawn from blog posts into any area of your regular site, and can dynamically update based on any one of unlimited categories you can assign to each post.
You can also, of course, display the blog itself entirely within your existing site design. SEO is hugely increased, and you can have greater levels of feedback from your site visitors.
Wordpress also comes with a vast number of (free) plugins, for events calendars, video & image galleries etc etc.
Highly recommend it.
