I like the DHTML folding/unfolding idea for the post.
I was thinking of doing something like tat myself.
However, I don’t think it’s intuitive for the reader what to do.
Readers of WordPress blogs are used to click on the title of a post to go to the one post plus comments page, so we have to somehow make it obvious to the reader where to click-
The well recognized symbol for this behaviour would be the [+]/[-] signs to the right in the title line.
Of course the whole title line should trigger the behaviour, not only the [+] icon.
It would also be nice if you could choose to close a post by clicking anywhere in the post text.
I like DHTML behaviours and have used it in a demo listing but I’m not so sure about what browser work it nicely.