Yes, this is very similar to Google's sitelinks but it appears Yahoo! has downplayed the Quick Links a lot.
For a search on walmart, now you get a link that reads Wal-Mart near you, taking you to Yahoo! Local. Back then, you saw they gave you a few Quick Links to store locator, online catalog and in-store now. Why did it change? Maybe based on their research, people only used the store locator link, so they figured to take them to Yahoo! Local instead of Walmart's store locator page.
A search on walmart at Google brings up sitelinks, but not really showing me things like store locator, which I would feel to be more useful then an electronics section.
So Yahoo! feels local results are what searchers want when they look for walmart, and Google feels searchers want to click deeper into a walmart department.
Back to Yahoo! Quick Links. Why did they change them? I still see "quick links" categorized for wikipedia results.
And also for some other type of searches, like group travel:
But what makes these happen? With Google, we believe it has to do with some authoritative status, plus a clear internal linking structure. What about with Yahoo!? I am not 100% sure.
Forum discussion at Search Engine Roundtable Forums.