What is journalism?

Well, apparently my creating a blog to improve my journalistic skills is pointless...because blogs aren't journalism. This is according to my online journalism professor anyway. We had our first class lecture tonight and she stated quite clearly that she thought blogs weren't journalism. Unfortunately she never did explain her point and so I am left with a foggy idea of what her feelings really are. In fact, she seemed to contradict herself quite a bit. First she said blogs weren't journalism but merely were someone's personal opinion. Then she said that journalism today often stems from online blogs as they are constantly bringing events into the forefront and or feeding the media new information. She also went on to say that journalists are always having to stay current and fresh, so therefore they no longer simply report on certain events but insert opinion etc. as well. I don't know, I am really impressed with this prof otherwise so I think if she had just explained herself a little bit more we would've understood why blogging should not be considered journalism. As of now though, I think I disagree. To me this sounds like a professional journalist creating an argument that is similar to the "high" and "low" culture debate. I may be new to the scene but last time I checked personal viewpoints and opinion was a huge part of journalism. Why is something that is written in the New York Times journalism and something that is written in a blog not? True there is a difference between musings and a carefully crafted article but can we not just put them in different categories of journalism? Say that one is approprite for one type of audience and the other appropriate for another? Is journalism not just words and ideas put together to form a story? Why do we bother to have different journalistic categories at all if something as important and current as blogging is just going to be unjustly dismissed? I think it is very irresponsible to think this way--Isn't it a bit presumptuous to assume you know what the root of journalism really is anyway?