One small nitpick: it doesn't always show the most recent printing. I believe it uses the same logic that the Edition field value sort in the Advanced Search interface uses, and so the printing that will be displayed is the one closest to the top of that list.
So for example, the card Deep Analysis was printed twice: once originally in Torment in 2002, and a second time in Ajani vs. Nicol Bolas in 2011. The 2011 version is clearly the more recent printing, but because of the unusual sort, the Torment printing is displayed by default.
For what it's worth, the sort order from lowest display priority to highest display priority seems to be:
The joke sets (Unhinged, Unglued)
The Portal sets
The Starter sets
The Promo set
Battle Royale, Beatdown, and Vanguard
The From the Vault sets in order from earliest released to latest
The Premium Deck Series in order from earliest released to latest
The Duel Deck Series in order from earliest released to latest
The multiplayer sets in order from earliest released to latest (Planechase, Archenemy, Commander, Planechase 2012)
The main sets in order of their release, starting with Alpha and currently ending with the 2013 Core Set
This means that an Alpha card has a higher default display priority than, say, the same card from a recent Duel Deck, Premium Deck, From the Vault box, and so on.