iWeb works great if you're a .Mac subscriber, but most people I know aren't and want to be able to publish their sites wherever they want, not just on Apple's server. Sandvox is a piece of software that works just as easily as iWeb only it allows you to publish your sites to any FTP, SFTP, or WebDAV site.
At this point the templates they provide aren't customizable but it is something they are going to be adding. Go sign up for the beta and give it a try while it's free.
