Sony Computer Entertainment is at last making its big push to merge the PlayStation Network into the "Sony Entertainment Network." The SEN earlier emerged from Qriosity's service last September. Part of the purpose of the firmware updates due this February 8th for all of Sony's gaming platforms (outside of the PlayStation Portable, interestingly enough) is to change all references to PSN into SEN instead.
For the time being this is a change in name only, but one that has been long in coming; Sony Computer Entertainment first revealed its intentions to make its PSN a part of the SEN back in August 2011. Sony's goal is to eventually tie what we knew as the PSN into a larger digital entertainment platform leveraged by the electronics giant's various consumer devices including televisions, smartphones, tablets and of course the trusty ol' PlayStation hardware. The SEN will also encompass the "Video Unlimited" video-on-demand and "Music Unlimited" services that were once part of Qriosity.
That means when your PSN account becomes an SEN account, you'll be able to use that one login across all of Sony's supported devices... and of course be billed across all of them through that same account.