The blog is handled with Wordpress. They had an existing blog and kept it there. I think two systems in this case makes sense. Using WP as a CMS is horrid, but it’s not bad as a simple blogging engine, and it’s free.
I’ve seen the add-ons to use MM as a blog, but I worry about running into the same trap with MM that a lot of WP developers do, which is trying to use a tool for much more than it was designed for.
I think a toolkit of MojoMotor for static pages, WP for blogging, Google Calendars for an event calendar and maybe Flickr for a photo gallery could do a wonderful job handling sites that aren’t big enough to take advantage of EE. All of those systems have (fairly) usable API’s, so it seems like it should be fairly easy to write add-ons to bring that content into MM, without muddying up the simplicity of creating content in each of those separate systems.