Maybe I'm the only one that thinks this, but Google Sites is a weird service. You can create a nice little website to call your own. You can do a lot with it, but there is a lot missing that shouldn't be. The "share this site" feature lets you allow other people to edit or view your site, but why? Maybe it's made for people to collaborate on a website, but why would you need to collaborate on a website?
Could a business use this? Or possibly a classroom application. I found it nearly useless for a blog (which is why I'm now using Blogger). I could make the site publicly viewable, but the comments are a completely different story. to be able to comment you also have to be able to edit the page. That is useless for me. If people are going to use this in a classroom setting I still think Blogger is a much better alternative for collaboration. Maybe it is just me.