It seems that a blog can give a pretty broad overview of what a person is like. Provided of course that this person takes the time to write up opinions, status, pet-peeves and such.
Now, if you go with the premise that a blog is a valuable tool to communicate who you are and what you are about. Then using your blog to tie all of your activities together seems to make a lot of sense.
One of those activities will be work, we all need to earn money and most of us are stuck doing it by working. Some of us have made the decision to stay with one or two employers, some of us have been at multiple employers throughout our careers. For some of us, our employers strongly suggest that we blog. Of course this is done to help communicate information to your customers, but it also helps make the employer's site THE place to come to for information.
If having more than one blog is unavoidable, then should you not make sure that there is a thread that ties all of your blogs together? This is what this blog is for to me.
Lets not forget also, that I can gain quite a bit from blogging on my employer's blog. Take for example my current employer, Sun Microsystems. Sun's web site is so high in rankings with Google, that anything coming off of it ends up being ranked pretty highly as well. This means that Google searches will show my stuff pretty highly in the results list. Try Googling for Eric Arseneau, almost all hits come to me.
The plan is to cross link between here and whatever blog I use with my current employer. Therefore providing a path throughout my employment life :)