The page gathers information regarding to how long companies promise to keep each of the mbed microcontrollers in production, via their longevity programs.
NXP: Longevity info - http://www.nxp.com/techzones/microcontrollers-techzone/longevity.html - Some parts available at least until 11/2022.
Freescale: Longevity info - http://www.freescale.com/webapp/sps/site/overview.jsp?code=PRDCT_LONGEVITY_HM - Kinetis family, availble at least until 7/2022.
ST: Longevity info - http://www.st.com/web/en/support/product_longevity.html - STM32 family, available at least until 1/2024.
Nordic semi: No longevity program. See http://www.nordicsemi.com/kor/layout/set/print/Nordic-FAQ/Silicon-Products/nRF51822/When-will-Nordic-Semiconductor-obsolete-End-of-Life-device-X
Silicon Labs: Silicon Labs commits to a minimum 10-year lifecycle - http://www.silabs.com/products/mcu/32-bit/Pages/longevity-commitment.aspx