Possible Clues:

• Online "Wow!"
• Modern version of 'Jumping Jehoshaphat!'
• What starts old Meldrew grumbling 'I don't believe it'?
• *Usher feat. will.i.am, 2010
• 'Wow!,' in an IM
• "Wow!" in texts
• On-line gasp
• 'Wow!,' in I.M.s
• 'Holy ... !!!'
• 'u can't b serious!'