Looks like Sony is making a move to get the Store up today, or at least prepping the service.

Starting soon, the PlayStation Network will be inaccessible for several hours for maintenance. The server maintenance performed at this time represents a crucial step in the full restoration for PSN, including the PlayStation Store.

During this maintenance period, users will be unable to sign in to PSN, though those that are already logged in should be able to remain online.

Resumption of full PlayStation Network service is still on track for this week in most regions.

Thank you once again for your patience as we work to return PSN to the highest level of service.

Via: PlayStation.Blog