Dolphin, the GameCube and Wii emulator - Forums

Qualcomm looks like they will be, Mali is the wildcard.

Because it's already implemented and live in the Nexus 6's Android M video drivers.

This time I'm more optimistic since N9 is covered with buffer_storage and base_vertex with GLES 3.2 release, Adreno will get support for both extentions (buffer_storage in v127 driver) and base_vertex with GLES 3.2 driver whatever it'll be and for Mali buffer_storage was recently raised with their product management team and base_vertex should come as part of GLES 3.2 driver. And that's not to mention Vulkan drivers that is coming for GLES 3.1 supported hardware

It's up to OEMs to push drivers or not, can't be 100% sure if v127 will be a standard for M, could happen later/earlier with a minor release or could never happen for some devices (there's a true mess with Vendors) since all the control in their hands, but I'd say most likely we'll see v127 or later with M for Adreno

As for the second part of your question:
By checking gfxbench database for the specific GPU, there you can see driver revisions and extensions that gets implemented/registered. As for Mali and upcoming driver features, it'smore like communicating personally with ARM staff on their developer forums (still they won't tell you about upcoming features plans/ETA but it's possible to monitor if something was raised for implementation/to request features if you're a developer and given solid reasons that they could agree with/get interested in), by monitoring events like SIGGRAPH and by checking documentation and release notes once new API/driver gets pushed. Pretty much it

Just enter your device name or custom search by GPU only, choose specific device/hardware, press info, scroll down to 3D API section and that'll show you all the extensions that are available. Example Nexus 6: https://goo.gl/len3Aj