The icons are just bigger, and they are all across the screen instead of in the bottom right. Scary, I know.
It's wouldn't be scary, if this were true....but I don't think it is. For example, the Skype app that runs on the start screen does not have all the functionality (and forces you to use a MS account) of the proper Skype app which runs on the desktop, so you need two separate apps. Internet explorer run from the start menu looks and behaves differently to the IE installed on the traditional desktop. The settings appear to be done in two places, there is the old style control panel and a new settings app under the metro start screen, but this can only be used for a subset of what you use the old control panel for.
I've only played with it for an hour or so, but to me it does not seem like it's properly integrated into the OS, it's just a bolt on, but at the same time, it's taken away some of the useful functions in Win 7.
Best case, MS have been very poor at getting across to users how to get started with Win 8. I like the look of the Metro interface, but it looks like they have only done half a job in integrating it with the OS.