Nokia released a new major firmware for Nokia 5230 (RM 588) Version. 

After Nokia 5233 the bigger brother Nokia 5230 recieves its new new firmware, too. it should be available in a few days via NSU or OTA.

here is a changelog for the firmware 21.0.004:

• there is no changelog known atm, but it will be shown here shortly

you can check here your product code, if it's available for you, too. or start your Nokia Software Updater (NSU).

if you find more changes or updates for this release, post a comment below.