I don't think there is a release date so may be a decent wait away.
What worries me is the fact that they are trying to morph the SP with the MP somehow. Sure hope it doesn't muck up the game.
Edit: Just found this info.
E.Y.E's release is delayed to an indeterminate date - we hope before the end of the year - in order to add 3 new chapters, new enemies, new researches and new secondary missions. But before all to balance these new features the best we can.
There are now more than 50 technology researches, 26 artifacts to find and over 120 secondary quests.