Couldn't find a topic about this yet, but it looks like Nvidia has an Nvidia Shield Portable v2 in the works:
WiFi certification site: https://www.wi-fi.org/product-finder-results?subcategories=11
Bluetooth certification site: https://www.bluetooth.org/tpg/QLI_viewQDL.cfm?qid=22779
It is being listed as "NVIDIA Shield Portable P2523"
From the looks of it, it will have Bluetooth 4.1, 802.11a/b/g/n/ac dual-band 2.4 GHz and 5 GHz WiFi, Android 5.0, and will have the Nvidia Tegra X1 processor.
If you were thinking about buying the original model at a jacked up price, might want to hold off until this is confirmed.
source: https://liliputing.com/2015/03/next-gen-nvidia-shield-portable-game-console-coming-soon.html
Will buy. The X1 looks damn sexy and it is way too far into the original Shields life span for me to really want to bite the bullet and buy one. If the X1 can run Dolphin at full speed holy shit...