E3 should never die. It's awesome.
Precisely this.
It's outdated, sure. It's corny, of course. It's probably more expensive than it's worth.
But it's also one of the few places for game fans to get hype after hype after hype. It's one of those few times when a bunch of friends can get together to witness unheard-of game content.
How many of us have sat there with a group of friends, while we all shout at the screen trying to guess which game is being revealed before the logo pops up? It's something not easily replicated by any other form of media.
It's also way better than any other comparable tech showcases. I love me some Nvidia, AMD, Intel, etc. conventions, but they pale in comparison to your typical E3. Blizzcon is good. Quakecon is good. Other 'cons' are usually solid. But none of them are equal to E3.
Sure, Sony and MS and Nintendo can all create their own separate showcases, but that misses some of the glory of E3. E3 is a combination of revealing new content, while also dick-waving and trying to one-up the competition. Having separate shows, entirely unrelated to each other, defeats some of the inherent feel of the show.
So even if it's corny and occasionally dull, and it creates hype for inevitable flops, E3 is still awesome.