[support] Multiple blogs, automatic cross posting

I think I already know the answer to this question, but I thought somebody might have better ideas.

My wife's blog is growing, and she wants to start a second one. We've got her blog pretty well organized into a taxonomy, and it's one particular term in the taxonomy that she wants to become a second blog. However, the posts she writes for the second blog should also show up in the first blog, along with comments, etc. So, essentially, what she wants is a second blog as a 'view' on the first blog. I guess that's the answer to my question. I need to create a view. Any other good ways to do this?

Also, each blog needs to be either its own domain or its own subdomain.