I've played the demo and will admit that it seems a bit underwhelming at first being in the classic Diablo style, ie more hack and slash rather than storytelling, but like Diablo again, Hellgate London doesn't seem to be addictive, but it gets to be.

@Zenicetus

I believe this phone in service is just their way of making sure that you aren't hacking since online is a significiant portion of the game. There will also be some marketing, but its supposed to fit in with the game's enviornment so any advertisement will blend in. As for copy protection, I believe that there is none, but don't quote me on that