This is a fantastic way to be able to blog on the fly. WordPress for the iPad and iPhone is very basic but if all you need to do is get the posts out there, it is a good option. I am posting this from my iPad.
I have limited formatting capability. Bold, italics, quotes, underlines, etc. If the goal is to live blog an event, this is perfect. If you want to make fancy edits, you will need the full web interface to make it work.
You can edit posts, pages, and comments. Do not expect to fully manage your site.