BBC micro:bit compatibility?

Is RISC OS able to run natively on the new BBC micro:bit?

If not, what is needed to make this happen?

Because, it should!

Is RISC OS able to run natively on the new BBC micro:bit?

Not at all. The micro:bit uses a Cortex-M0 series processor. That’s about powerful enough to run a toaster. The memory is going to be one of 256 KiB flash + 32 KiB RAM, or half that. Bluetooth is onboard because it is basically a proprietary Bluetooth SoC running this thing. https://www.nordicsemi.com/eng/Products/Bluetooth-Smart-Bluetooth-low-energy/nRF51822

If not, what is needed to make this happen?

A miracle? 32KiB (or 16KiB) of RAM is tiny, RISC OS’s “page zero” and scratch space is twice that. There is no video output. There may be no USB host mode (the USB socket shown on the BBC site is a “device” socket, like a mobile phone, so the micro:bit may appear as a device you can interact with rather than something you can plug keyboards and mice in to – so how to even type commands and view the result? some sort of serial, perhaps?). Oh, and the Cortex-M0 is about as different from the Cortex-A8 (etc) as a Reliant Robin is from a Lamborghini. Both are cars. That’s about where the similarities end. ;-)

Still… Want one!
I have a crappy old washing machine. This, some breadboard, and an little OLED panel with bit-bashed IIC… ought to do the job nicely.