The latest update has arrived for the Nintendo 3DS bringing the 3DS system up to version 9.5.0-23. This update is nothing special focusing most specifically on stability.
Nintendo’s official patch note for today’s update states: “Further improvements to overall system stability and other minor adjustments have been made to enhance the user experience.”
Another thing that has been addressed with this update is the region free hack on the 3DS, the "RegionThree" hack has been destroyed by this update and at this point it is uncertain what the future of these hacks will be. If you have access to the region free hack then when you update the system it will be gone which I personally recommend.
If you plan to use the eShop you will need to update your system.