The update includes a total of five pre-installed themes that users can try out right now. While these free ones aren't particularly exciting—offering little more than a color swap—gamers willing to shell out a bit of cash can also purchase premium themes from Nintendo's online store.
I for one am eyeing the Zelda: A Link Between Worlds theme.
System Update 9.0 also adds pop-out notifications, which prompt you with SpotPass notifications over the Home Screen. Nothing groundbreaking but a welcomed addition nonetheless.