Setting up a meta blog for a group of blogs

I’d like to find out whether I can use WordPress to set up a meta-blog – a bit like WordPress.com – that can create tag clouds from the tags generated by a select group of 10 bloggers. I’d like also to be able to excerpt some of the blog posts from the select group as a way of showcasing what’s going on with the blogs.

This is likely a possibility – but can anyone give me a pointer as to plugins I might want to use – or does anyone know of this sort of thing in action?

Any advice much appreciated