Bye bye ARM Mali =(
Now, every reference-implementation ARM processor manufactured will fund GeForce desktop products, datacenter/enterprise, etc as well.
NVIDIA definitely needs something like this in the face of the new Samsung deal, as well as AMD's pre-existing console deals.
GPU profits should be able to cover their own R&D, especially given the obscene prices on the high end cards.
That's like throwing pennies onto a pile of gold. NVIDIA makes billions of yearly revenue. ARM makes ~300 million. NVIDIA revenue is 60% of a GPU price. ARM margins in IoT/embedded/phone chips are thin-to-non-existent. If anything, NVIDIA will need to cut GPU spending to push ARM to the moon. And the announcement already suggest that this will happen.
That margins on $1 microcontroller are "thin-to-non-existent" is thus completely irrelevant - those are margins of the silicon manufacturer, not ARM's.
Console makers dictated that RDNA must use a forward-compatible version of the GCN ISA. While AMD might have wanted to make some changes of some ideas that turned out to be less-than-optimal, they cannot because they are stopped by the console makers paying the bills.
Mali support is done by outside groups (not ARM). Midgard and Bifrost models are well supported (anything that starts with a T or G, respectively). Support for older models is a little worse, but better than some other GPUs.
Adreno support is done by outside groups (not Qualcomm) and is lagging behind new GPUs that come out considerably.
PowerVR GPUs (Imagination) have terrible open source support.
They did contribute somewhat to the "tegra" driver at least.