From the edublog (I'm migrating those here, so I can have just one teaching blog):
Last year, I had one WordPress account and had all my students post on that one. It really wasn’t all that great, in the long run. This year, I want them each to have their own account. I want them to experience the fun of “prettying it up” as well as seeing their words in print. This year, I also want them to comment on other people’s blogs, both inside and outside of our classroom. Wish me luck!
UPDATE on 7/18/2012: Some of the students got their blog "prettied up" and a couple even got something posted. The problem was primarily that we had planned, with the principal's permission, to actually get to use the computer lab. Then she decided that only RTI could use it, and our techy said that the students weren't allowed to use the classroom computer; it was for teacher use only. That pretty much ended the whole blog thing.