Starting off as a mis-type on the keyboard (she meant to type "you're wonderful" but typed "you're wunderfuk", it soon took off between my friend and I, just as "pwn" took off on the 'Net.
The word is self-explanatory, I think. It can be used as a noun or a proper noun.
"He/she's wonderfuk". "Hey, you, Wonderfuk!"
