I believe it depends of how you look at E3.
I personally await year after year E3 because of the spectacle, the new announcements, the hype of the show and the reveals.
What im trying to say is that i agree with BMaker11.
In my opinion, the show doesnt have the same shock factor when you are revealing almost the same games for 3 years in a row.
Yeah, it would be ideal for ALL companies to take the Bethesda route with Fallout 4. Showing the game with a release date the same year. But sadly they are the minority on this business.