After months of examining options, we have decided to go with WordPress as our blogging platform of choice. Further, we decided to let WordPress host it! The reasons are many, having mostly to do with ease of use and search engine friendliness. The hosted site is automatically and regularly upgraded to the latest release, includes a number of great features such as an extensive template library, customizations (for VERY small fee), and search engines love it.
We offer other blogging platforms, including embedded solutions, for our many clients, and WordPress remains at the top of the heap.