I am thinking probably just an incremental step up in CPU. But with raspberry themselves half killing the Pi form factor I am not sure if its as relevant.
The rk3588 is some time away and the 3399 hopefully has quite a long Eol that I am not sure if the rk3399 pro is much of an upgrade or even if worthwhile.
Radxa have spent a lot of invested time with Rockchip and I don’t think that was a bad idea.
It would be great to maybe have more pcie maybe 2x the current as the modular nature it adds more than any other dedicated device as it can be many.
If we had a wish list in 3-5 years time then a rk3588 2/4/8 gb ram offering.
2.5gb ethernet, 2x usb C with 2x m.2 4x lanes.
Not sure now if m.2 is the best idea for a SBC due to available product but maybe some form of riser to full pcie connector might be a better offering. As we have learnt its what is available as a peripheral is the important thing.
I think Radxa have probably learnt loads from the RockPi4 and its quite interesting as currently it provides entry level computing, but four ARM Cortex-A55 cores and four ARM Cortex-A76 cores coupled with a Mali G52 GPU is actually a pretty amazing device.
That is long term and purely wish for and price somewhere of 100$ but we will have to see what happens with the price of ram.
I am think the next rockpi like the rockpis is likely to be much more humble like the rockpis presuming we might see something like the RK1808 that is an AI specific purpose for vision/voice/gesture applications.
It may not even be a RockPi might be the pciex4 switch to x4 endpoints utilizing some of the cheaper current automotive silicon available as we might even see multiple rk1808 devices linking to the next gen but got a feeling that might be via USB.
Might even be a RockPi0 as the RPI0 is actually my favourite SBC its a wonderfully tiny cheap and useful device, that is just lacking slightly and there could be a market, but really that is already covered by the RockPiS.
My bet is RockPiAI with the RK1808 that is a tiny format that will be an extremely unique and powerful.
Its looking like they could be used in multiples as first stage i/o processor for rk3399/rk3588 coordinators.
RT-linux maybe risc rather than general purpose application linux.