Xiaomi will soon bring Android 7.0 Nougat to several handsets
In a nutshell, beta testing is well underway. Per Xiaomi's MIUI operations manager, the Mi 4c, Mi 4s and Mi Note will be among the first to receive Android Nougat in the near future. There's no word on when newer handsets like the Mi Note 2, Mi 5s Plus or Mi MIX will be updated, but presumably, they'll be given their just desserts in good time.
MIUI, as you'll probably be aware, is Xiaomi's own custom fork of Android. Whilst we haven't seen much by way of features, a previous leaked screenshot has offered a flavor of the Nougat-based MIUI 9. That same report indicated that Xiaomi would begin to push the update over the December-January period, so here's hoping that Xiaomi can get the wheels in motion sooner rather than later.
Should we hear any further news on Xiaomi's firmware update plans, we'll be sure to pass them on.