We were having a family bible study last night and discussing this very verse.  We were telling the kids that this verse is only found in the KJV (and NKJV?).  The discussion was on why we read the KJV and no longer the NIV.  This verse was one of the reasons we were convinced that the NIV as a corrupt version so we stopped reading it.  To think that the most important trinity verse has been taken out of all the other bibles.