This system update indicates the biggest change to the eShop since it launched, but don't get too excited: it's mainly setting the foundations for new features that will become available in the future. Here's an overview of what's available now.
Redeem Download Code
This option lets you input a 16-digit code to claim a download, paving the way for easier competitions and distribution of games: Nintendo Europe's free 3D Classics: Kid Icarus will use redeem codes, for instance.
At the moment there is nothing you can do with this option until an eShop publisher releases codes.
Save Credit Card Details
Here's something that's been requested an awful lot: you can now save your credit card details to your 3DS system so you don't need to type them in every time you want to make a purchase. You must still buy currency in blocks, though.
The details are saved to your console itself rather than the Nintendo servers, so it should be pretty secure, but as always these things are at your own risk.
Add Required Amount of Funds
Here's a very welcome feature: the ability to add just the right amount to your eShop balance.
The trick is not to head to the usual Add Funds screen, as that only offers the regular denominations.
When attempting to purchase software, if you have insufficient funds the store will prompt you to add more. Select "Add funds using a credit card" and "Add required amount only" at the bottom — this automatically adds the shortfall to your account.
No longer will you have to add £10 if you're £2 short. Very good news indeed.
The system update paves the way for demos to arrive in the future.
At the moment there are no demos, and we do not know when demos will be available. Nintendo's official statement is:
Users will have the option to play demo versions of select Nintendo 3DS releases, enabling players to try a game before making a purchase decision. Whether a demo will be made for a particular software is decided by the publisher of that software.
When we know more about demos, we'll update you.
Sleep Mode Downloads
Here's another welcome improvement: the 3DS can now download software and videos during sleep mode. It supports multiple downloads too, so you can do your shopping and come back later and find new games waiting for you.
Next: System Transfer Tool