As you can see from the background of this blog, my current visual brand, in the blogosphere ate least, is slightly unimaginative. This is not for want of trying, but rather because of a lack of experience of blogspot and a limited time to spend 'playing' with colours, templates and pictures.
I fully agree that the visual impact of someone, whether in person or online, has to be smart, distinct and memorable, so I will try to spend a little more time perfecting my blog's visuals.
I'm not sure that I agree that a visual brand has to be consistent; the major factor that I see in this is time: today I may enjoy a black background and a picture of the American West. In a few years time I might prefer something different, but I am not sure that I would then want to retrospectively change any past blogs.
Another factor in this is audience; although I don't have business cards, I am not sure that I would want them to have the same theme as my blog: whilst a blog can reflect personality, I would want my business cards to reflect nothing but professionalism. Perhaps if and when I have business cards I can think of a compromise..
