It appears that nothing special happens to long-standing unapproved nodes. Consider, for example, HELP! - trouble returning values. That was posted in September and is still unapproved.

I found that by going to Seekers of Perl Wisdom, selecting the "Next" link at the bottom, then editing the URL that my browser showed to change "next=20" to "next=1500" and scrolled down to the bottom looking for unapproved content. Then select "Next" and scroll to the bottom until some unapproved content appears (you need to be level 6 or above for the unapproved content to be shown at the bottom of each page).