I guess blogging can be a lot like journaling. You write what you are thinking and feeling. The question is whether people want to read about what you are thinking and feeling. I could (and probably will) write about mundane everyday things. However people can relate to those ordinary things so maybe they would enjoy reading and/or feel more connected to the world by reading my blog?
I'm kind of hoping that by writing more I will become a better writer and be able to write more interesting things for people to read, but for now you are stuck with my day to day ramblings (no one is currently reading this anyway).
I think one of the things I would enjoy about having a blog versus a journal would be the ability for people to comment on my rambling. I would love for discussions to take place and for my blog to be a place where people get and exchange ideas.