You will eventually have to go the way of multi-blogging, otherwise your single blog with end up becoming a bhanumati ka pitara.
This is particularly so if you take interest in diverse subject and write on them too.
I am a multi-blogger myself. I have three blogs, my hold-all blog jaihindi, which is my first blog into which I used to stuff everything. But it soon became too unweildy.
I then wanted to write a tutorial on C programming and even I could see that including that into jaihindi would make it burst at the seems. So I spawned off a new blog printf-scanf.
I thent wanted put a Hindi translation of a Malayalam classic that I had done onto blogsphere. Again jaihindi would have crashed if I had stuffed it into it and clearly this was a subject that couldn't go into a blog on C programming. That is how my third blog keralpuran came into being.
A have a couple of more ideas churning in my mind, and very soon blogosphere is going to be plagued more of my new blogs.
The traffic issue won't be such a problem if the subject of the different blogs are mutually exclusive as in my case. In fact, it will improve traffic. Take my own case. If had stuffed all my posts including the Malayalam thing and the C programming articles into my jaihindi blogs, my readers would have been so disgusted that they would not have deigned to touch my blog with a barge pole. So I would have lost readership by having a single blog.