Don't expect to connect to the PSN on Monday January 27th between the hours of 9:30am and 3:30pm PT as the network will be down for maintenance. European users will be without the PSN from 5:30pm and 11:30pm GMT.
The services that will be taken down include the PS Store, PlayStation Home (that's still a thing?), and Account Management, but the Blog has notified users that "If you've signed in to PlayStation Network any time since January 20th you will be able to play games online and access partner apps such as Netflix during this maintenance period," so that's good news.
No further detail has been released as to what maintenance Sony is performing but all can be glad it only lasts 6 hours.