To me, yes. Of course, blogs vary in format from microblogging to captioned image galleries to diaries to long-form opinion pieces, but I've found that the larger landscape of writing can be similarly broad and all-encompassing.

I think the most critical thing for this community would be that you're posting your own original work, and not someone else's.

Writing is writing in my opinion, doesn't matter what format or what the content is as long as it's yours and not plagarized. Keep doing it and keep talking about it, you'll only get better.

Not to beat a dead horse, but yes it is writing. If you are being creative and putting words on the screen/paper then it is writing. Also in my freshman year of college I took a writing course and the first thing we did each day was write on blogger, so it's only cemented my belief that blogging=writing.

I personally think so. It's like reading a dairy style biography to me. I like reading things that are a little raw and unpolished.

Blogging was my entry point to writing. It's useful to see what kind of content people are interested in. Plus they say that you need to write some 100,000 words before you're half decent at grammar, sentence structure, style, tone, etc. and blog writing is a fairly safe way to get the hang of it.
Sometimes I'll read my old blog posts and laugh at how bad they are, but that's ok. I'm a better writer now as a result.