To each his own. If you prefer the blog format, by all means keep blogging. If you prefer twitter, go do that..
Of course, if you intend to use your blog to make some dinero and pay some of the bills, it's probably not going to work... but neither will twitter or facebook for that matter. If you just want to express yourself, use whatever you want and whatever your public will use.
And can't you have a blog AND twitter, facebook, etc?