I think that it will be at least several years before properly working online features are implemented in CEMU, but I highly doubt that the Nintendo Network will ever be supported. Any future CEMU online play features will probably involve custom servers instead of Nintendo's official ones.
I actually ended up calling the number (with the first seven digits (1-800-925-5633) associated with the "YALLNEEDIOSU" part), but instead of IOSU, I got a woman who said:
Welcome to America's Hottest Hotline! Ladies, to talk to interesting and exciting guys free, press 1 now! Guys, hot ladies are waiting to talk to you! Press 2 to connect free now! Ladies, press 1 now! Guys, press 2 now!
PhoneSexploit confirmed?