RE: What elements doth a good blog post make?
First of all I think it is worth noting that "good" is ultimately a question of oh-so-subjective value judgments. What one person may consider a good post, the very next may consider trash.
That said, I am of the opinion that above all a good blog post is one that the blogger enjoyed writing. If one isn't enjoying blogging, it's likely that this will shine through in the tone of his writing.
A good post should fulfill the blogger's desire for self expression.
The blogger's personality should shine through in the tone of the writing.
Ideally a good blog post would be read by a fair sized audience but popularity is not always an indicator of quality and a small faithful audience is just as worthy as a larger one.
Humor always helps.
If you're discussing anything you wouldn't want people you know in real life to stumble across, it would be wise to place that entry under a security lock, making it viewable to only those you wish to have viewing it.
Separation between paragraphs make it so much easier on the reader's eyes. I'm far more likely to read a post with them than without them.
A good blog post does not include TYpInG LiEk ThIs.
Likewise, CAPSLOCK IS CRUISE CONTROL FOR COOL. Use it sparingly.
Simply put, a good post is written using one's own common sense about reasonable grammar and punctuation. The reader should not have to struggle to translate entries written in their own language.
I think it's pretty silly to go into what kind of content makes for a good post considering all the different kinds of blogs out there. I think it's enough to say the content can be whatever the writer chooses as long as he or she is interested in it.