Nintendo recently released a new firmware update tagged as 4.4.0-10U. European and Japan 3DS owners also receive the update as 4.4.0-10E and 4.4.0-10J respectively.
While nothing has been revealed about the update so far, speculations say that it might be an update blocking flash carts such as Acekard 2i and SCDS2 (serves you right), overall system stability and improved user experience. As far as the user experience go, it's very easy to notice the change in folder icons where there is a paper inserted if the folder has contents.
Remember that you can also automatically receive the update if you're connected to a wireless access point. If not, you'll be prompted to do so if you access the eShop or simply go to your system settings -> other settings and then system update.