Raspberry Pi released a new version of pico-sdk for RP2040 and RP2350. It boosts the RP2040's maximum rated clock speed to 200MHz. Graham Sanderson explains that with a regulator voltage of at least 1.15 volts, RP2040 can run at 200MHz and it can be selected by setting SYS_CLK_MHZ=200 via preprocessor define. If you have a Raspberry Pi Pico, Pico W or other RP2040-based board, you can now run it at 200MHz.
The RP2040 launched in January 2021 as Raspberry Pi's first in-house microcontroller chip with a 125MHz stock clock speed. Tinkerers have overclocked it before but it was out of spec. Now the 125MHz limit is lifted. The RP2040 runs faster than the later RP2350 family based on the more powerful Arm Cortex-M33 core and open-silicon Hazard3 RISC-V cores, but the RP2040's Cortex-M0+ cores at a faster clock speed still offer good performance for common workloads.
Sanderson hints that new frequencies may be certified for different platforms in the future. More details are in the pico-sdk release notes. The new clockspeed isn't enabled by default due to backwards-compatibility concerns. Those who want to enable it should set PICO_USE_FASTEST_SUPPORTED_CLOCK=1 in CMake or as a preprocessor definition, which is forwards-compatible with other clockspeed boosts for supported chips.