I Corinthians 4:8

Now ye are full, now ye are rich, ye have reigned as kings without us: and I would to God ye did reign, that we also might reign with you (KJV)

Then: Either on a rhetorical roll or highly upset that some Corinthians would still block out his teachings, Paul speaks sarcastically. "Now." They act like the last days are in effect. Already they are rich kings reigning in eternity. How absolutely wonderful if Paul, Apollos, and all the other apostles could reign right along with them. The Corinthians are marking themselves as unable to attain greater riches in glory because of the pride which surrounds their minds (Henry).

Now: If the fanciful statements like "ye are full" are not enough to let us feel Paul's sarcasm, we have confirmation in the phrase, "I would to God ye did reign." The Greek text lacks the words "to God," but Hodge (p. 72) believes that saying "Would ye did reign" is still enough to show Paul's derision. Morris (p. 76) refers readers to Matthew 5:6, Christ's teaching that we need to hunger and thirst for righteousness. Our goal is to keep wanting more and to stay continually in the Lord's service. Christ calls us to keep growing. He does not want us to be like the self-deluded Corinthians.

Extra source: Commentary on the Whole Bible Acts to Revelation Vol VI by Matthew Henry online at http://www.ccel.org/ccel/henry/mhc6.iCor.v.html
Commentary on the First Epistle to the Corinthians by Charles Hodge (Grand Rapids MI: Eerdman's, c1950, 1995) online at http://books.google.com/books?id=p_eicwvOhUAC&dq=Corinthians+commentary+Hodge&printsec=frontcover&source=bl&ots=N5y0XtoVzJ&sig=ho-hOQGsur5Q_AT-t9joFxZjDrc&hl=en&ei=jtQ4S8-tHdOhlAf_t9GeBw&sa=X&oi=book_result&ct=result&resnum=8&ved=0CCEQ6AEwBw#v=onepage&q=&f=false
The First epistle of Paul to the Corinthians: an introduction and commentary by Leon Morris (Grand Rapids MI: Eerdman's Press, 2002) online http://books.google.com/books?id=lNc0AYIqQvAC&dq=Corinthians+Morris&printsec=frontcover&source=bl&ots=NwNTeWfd4I&sig=XgqcdeZIJ7jIfOrxTT7PUqQqo_4&hl=en&ei=F-MkS82TPIvWlAfW55D-CQ&sa=X&oi=book_result&ct=result&resnum=2&ved=0CAwQ6AEwATgK#v=onepage&q=&f=false