Take this information with a pinch of salt but according to Nintendo Enthusiast the Nintendo Network will bring new features that haven’t been used before by Nintendo and the network itself will be a rival to Microsoft’s Xbox Live and Sony’s PlayStation Network.
“A source that wished to remain anonymous has told us that Nintendo will launch a website accessible from any web browser that will handle configuration of your Nintendo Network account for use on the Wii U or 3DS. He also stated that Nintendo Network will include many new features that haven’t been used before by Nintendo. According to his accounts: Nintendo Network = Sony PSN = Xbox Live.”
Thanks to Christian for the Nintendo Network image