If famousmortimer is right, then Sony is doing everything right...except for games, lol.
Even if they think they'll sell out for the holidays most of the time, they should show that they have at least some bigger games in development, so the people won't see the XB1 as a good alternative and buy it instead.
The reasons why Sony won the E3 are almost all gone and the games wasn't one of them (MS was in fact much better, because they showed a lot of stuff from late next year).
If MS again has a better showing on gamescom, Sony will lose more and more from the really strong momentum they had, since games is what people buy consoles for.
They have to show a strong lineup before launch, so the people will wait to get a PS4 even when it's sold out and don't look too much on the alternatives.
The goal should be to get a decent enough difference in hardware base between PS4 and XB1 as fast as possible. For that you have to be acting and not hold everything back for reacting.