Sony have started releasing Firmware Update 6.00 for PlayStation 4 to the general public. It's just under 450 MB, and we're not precisely sure what has changed just yet — but we expect PlayStation to let us know at some point today.
The patch notes are a little vague...
Having just installed the update, no major features have immediately been apparent. During the update's Beta phase, participants noted that the 6.00 Beta did not include any significant features — though the terminology Sony used during the Beta invites specifically said "System Software 6.00 does not include any major consumer-facing features during the beta period
One immediately noticeable difference compared to moments before the update is a speed improvement in some dashboard features. Specifically, the Trophies sub-menu under each game tile is loading significantly quicker, and the full trophy list appears more rapidly if you select the overview. This would be a pretty mundane update if this was the only feature but it does suggest that the on-board OS has a better sync with PlayStation Network.
It's entirely possible that Sony have not included anything more exciting in 6.00, despite it being a full numbered update. However it's also possible that Sony are keeping back a more significant new feature, possibly related to PSN, for an official announcement on the Blog. We will let you know if we find anything interesting as we test out the new update.