In It's the thought that counts by James Silver of The Guardian it is argued that "an ever-growing band of media personalities are turning to blogging as a means of increasing their profile." He goes on to suggest no self-respecting columnist can survive without a blog.
The advantages of blogging, however, seems to be less about following an Internet trend and more about a number of other factors that include:
1) Having all your musings in one place
2) Being part of a blogging community
3) Enables the writer to construct an all-round image of their personality
4) Blogs provide quick commentary on rapidly unfolding events5) It offers unlimited space to say what you want
6) It represents instant two-way communication of quite complicated thoughts
7) Blogging is a way of cutting out editors and publishers
Sounds like good enough reasons to me!