In an email to PlayStation Network subscribers, Sony told users that their accounts will now be known as "Sony Entertainment Network" accounts. Not that this does away with PlayStation Network as a name. Sony says PSN "will be aligned with Sony Entertainment Network".
It's a purely cosmetic change, in other words and no, it has no effect on either your PSN login, password or anything. "This transition is based on Sony's goal to enhance its unique digital entertainment offering," Sony said in an email to subscribers. "This helps us get closer to our goal of establishing a global comprehensive network platform of services across games, movies, music and more, all accessible from one convenient account."
Notably, PSN accounts on the PSP will not be given the name change. The rebranding will take effect in the next software update for the PS3, due to roll out February 8.