If you are thinking of having a blog, you should have some idea what you are writing about. There is tons of stuff you could write about other than yourself. I own few blogs and it is all about different stuff. Here is some idea.
- Personal Blog
- Business Blog
- Hobby Blog
- Blog about Blog
Other than that, you should know that Worpress is a very powerful script and easily altered to different usage. ie Classifieds, Directory, Publishing Website and maybe some new idea you can think of.