I think they're refering more to the reaction.
Next year they may only show Zelda and highlight old games, but that's not the point. Iwata is talking about exciting the public, this year they announced some pretty big games but the way they showed them was not sufficient toe xcite the public.
New SuperMario Bros. Wii was their BIG BIG game announcement, but with the four people just playing on stage it looked a little cheap. That's what he's referencing to, and he's absolutely right.
They may show fewer games, just look at E3 2004, that was basically one new game and the DS. The rest was pretty much known, but it was delivered in a way that created excitement. It's a lot more about the presentation itself.
I think expectations are a little higher and the competition is very fierce so I don't think they can deliver the goods in terms of excitement at E3. I think they have a better chance at their own event in October, where there is no competition and they can set their own tone.
But they can certainly improve fromthis year, despite the fact that many games were shown I don't think it was actually much better in terms of excitement than E3 2008 was. And that has nothing to do with the games, it was once again the setting and the vibe of all competitors plus their own.