mbed EoL announced

ARM has announced that mbed will hit End of Life July 2026.

This article has a lot of good links and sources to cover the issue.

Thus we need to discuss the status of the mbed-based official Arduino core for the RP2040 and its community created alternative, the arduino-pico core.

Someone has already raised an issue on ArduinoCore-mbed about the EoL, we'll see how the discussion develops in that context there, but so far Arduino has yet to reply to anyone on this issue.

There has been significant development on the arduino-pico core, so I don't think it should surprise anyone that one possibility to resolve the EoL is to transition to treating the arduino-pico core as a first-party core in the future, and possibly replace and even delist ArduinoCore-mbed at some point.

RP2040 Arduino development is at least lucky in the mbed ecosystem to have an alternative implementation available.

edit:
Other places of discussion.
Arduino Forums
PlatformIO Forums

Start by reading the linked ArduinoCore-mbed issue, the arduino-pico core, and the platformio/platform-raspberrypi pull request, along with the referenced forum discussions. Done requires a maintainer decision on the future status of ArduinoCore-mbed and whether arduino-pico should become a first-party alternative.