I realise this is MSE, but please let me point out the importance of this feature for StackOverflow specifically.
While StackOverflow is ever growing, I find this feature is getting more and more necessary.
It has been a point of discussion on MSO before that question quality, in general, is dropping, see here and here for example and I'm sure there are similar discussions because the two I link to are highly upvoted.
Yesterday I was reading a discussion on MSE, where someone was venting his feelings about the fact that SO tends to reward low-quality quick answers more than high-quality detailed answers, and that he simply saw no reason anymore to invest a lot of time in writing detailed answers.
Someone said, in my opinion rightly so, that the problem lies in the fact that the front page is dominated by users who just want to give answers quickly to solve the simple problems that most askers have. It isn't a good place for those guys who really want to help out by giving as much detail as possible to an answer, and help solving complex questions that require more than 5 minutes of thought.
The place where these answerers want to be is the featured tab, and now the necessity of expanding this tab with such things as advanced search options becomes obvious. In my opinion, these ambitious answerers are the most important when it comes to SO's philosophy of building a library of knowledge that contains detailed answers and re-usable solutions to as much problems as possible.
If we want to keep the good answerers, at least have the featured tab make some sense. It begins with this very feature request, making it filterable and searchable as a seperate region of the site.