It's only a matter of time before Moblogs hit the mainstream. Clearly this is something the mobile operators will encourage and so many people have camera phones & love sharing pictures. Moblogs are likely to be seen as requiring less effort than text oriented Blogs.
The thing is that sharing pictures on such as scale could lead to privacy concerns. What if someone posts a picture that includes an image of you in the background? It's unlikely that the "photographer"/snapper is going to request your consent before posting - they may not even notice that you're in the picture.
Imagine if you were somewhere or with someone that you didn't want your partner or employer to know about?
OK so currently the resolution of most camera phones is pretty low and hence such backgrounds aren't likely to be recognisable but it's only a matter of time before 2 mega pixel camera phones are popular and then this could be more of a problem.