Doesn’t really do much.
The latest PS4 firmware update, update 4.74, is available now- and like all non full version updates for PS4, it seems to do absolutely nothing. The patch notes cite only system performance improvements as changes, which is just a euphemism for the vaunted ‘stability’ updates that consoles are so famous for.
Of course, others are reporting that there is in fact a change- update 4.74 terminates beta access to PS4 update 5.00, the next major PS4 firmware update that should be releasing some time soon, and which selected users got to beta test earlier this year. Now, those beta testers too will have to wait until the rest of us gain access to it.
As for PS4 update 5.00, that one sounds very disappointing- not a whole lot of major new features or changes are planned. Albeit, of course, the PS4 OS is pretty close to as good as it will be anyway- so maybe that does make sense.