EA have confirmed that online EA titles on Wii U will have to share account information as part of the Origin Engine.
By signing up to play EA's titles, you agree that limited user account information can be transferred to EA. Information transferred to EA includes your Mii information, email address, Nintendo Network ID, friend list, country, language and date of birth but does not include credit card number or other financial account information
There was rumblings in the past that the online focus between EA and Nintendo was shakey due to the need for Origin, but by the sounds of things future Wii U titles from the publisher will support online play.
The document also notes "Nintendo Network ID", which is the likely successor to the archaic friend codes system.