So far Blizzard Entertainment will not be at E3 2009, (they also skipped E3 2008) however Activision-Blizzard will present this year. Its somewhat fluffy what it means. There is still a chance for we will see some World of Warcraft, Starcraft 2 or Diablo 3 news update at E3.
Here is an official statement from Blizzard representative:
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