You know, I never doubted that those particular types of links (for Google Finance, Google Health, and other Mountain View-operated web services) were hard-coded. I don't think Google ever said otherwise, either, for these particular verticals.
Particularly interesting is Marissa Mayer's comment in this video from 2007 [youtube.com]
"When we roll[ed] out Google Finance, we did put the Google link first. It seems only fair, right? We do all the work for the search page and all these other things, so we do put it first...That has actually been our policy, since then, because of Finance. So for Google Maps again, it's the first link."