Samsung has just released the expected Android 4.1.2 Jelly Bean update for the Samsung Galaxy Note 10.1.
At the moment this is only available for devices in Germany, but is likely to get to see other countries in the coming days.
The Android 4.1.2 update can be applied through Samsung Kies or OTA services from Samsung. To check if you can upgrade, you have to enter the menu Settings> About tablet> Software Updates.
If you have not received the update you can apply manually downloading the ROM XXCMA1 from here, and do a flash with ODIN.