The PSN store is about to get an overhaul next week
and Sony's announced some planned PSN maintenance prior to the relaunch. This Monday, October 15, from 4am PT/7am ET until 4pm PT/7am ET, PSN will experience some downtime.
If you've logged into PSN over the past few days or make some time to do so this weekend, you shouldn't be affected. That's not to say you'll have access to all of PSN, though – during the downtime, the PSN Store, PlayStation Home and Account Management sections of PSN will be unavailable.