An interesting move, given MoveableType's recent licensing changes. I haven't tried Radio Userland. I did try using Frontier in my by-gone Mac days and met Dave Winer at a MacWorld in 1995.
Even though some think that blogging is now passé, I think it is actually starting a renaissance. With the explosion of RSS and ATOM syndication and webfeed readers, now you can blog and more people can easily review your content. Sure there will be a lot of drivel and dreck out there in blog land, but there's a lot of drivel and dreck out there as just plain old html websites. No one is saying web pages are passé are they?
I foresee that blogging/RSS/ATOM will become in the next 6-12 months the preeminent way for companies especially to transmit press releases, update notifications, and other news.