Yeah we've made some tweaks to the way its picked. First off, it is now totally automated.
Second, we have been making the rating criteria far more strict, so that it will do a better job of looking back over the last week/month and picking thee BEST stuff. Not perfect yet, but getting there. eheath you are correct, the date is when the video was uploaded not when it was picked.
It picks one video at midnight that is the 'best' video it can find. It can look anywhere from yesterday to 365 days ago, depending on if it finds top quality with a scaling minimum number of votes.
That vinnycash edit was pretty awesome if you ask me.