Wordpress came from b2. It's a far superior product - the amount of plugins out there are just the icing on the cake. It's supremely flexible, about as powerful as they get, and I haven't yet found anything that I can't do with it.
check it out being used by Ford.
http://autoshows.ford.com/
there's an excellent feature to import from an RSS Feed as well as a variety of other blogs.
You get better control over your wordpress blog if you host it yourself. Try it out - I don't think you'll be disappointed.