The Mi 5s isn't the only top of the line device Xiaomi is currently working on, as it turns out. Alongside the refresh for its normal-sized flagship, it's also apparently going to finally launch a successor to the Mi Note phablet from 2015 (which is pictured below).

The Mi Note 2 has definitely been a very long time in the making, but it's said to become available in the next few months, if a new rumor out of China is to be believed.

Furthermore, we should expect not one, not two, but three different hardware versions for the phone. The Standard model will feature a single camera on the back, a Hi-Fi chip, and a 'regular' quick charge function.
The High version will unsurprisingly take things up a notch with a dual-camera setup on the back, as well as a 'super quick charging' feature - and will keep the Hi-Fi chip.
Finally, the top of the line version will bring with it a curved display reminiscent of Samsung's edge line (which has in fact been rumored before for the Mi Note 2). This will also have a higher-end Hi-Fi chip and the 'super quick charging' too.
Unfortunately the source for all of this information hasn't gone into any details about what any of these things ("Hi-Fi chip", "super quick charging" for example) actually mean. So right now it's anyone's guess.
One thing that is clear is that like the original Mi Note, the Mi Note 2 is going to be a high-end device. And with the curved edge screen it might prove to be an interesting competitor for Samsung's upcoming Note 7, which will also go the edge route.
There's nothing new in this report about specific hardware inside the Mi Note 2, but you should expect to see a 5.7-inch (or so) QHD touchscreen (at least in one of the higher-end variations), Qualcomm's Snapdragon 820 or 823 at the helm, and up to 6GB of RAM.