The gameplay footage of InFamous is absolutely amazing.
I dont think either KZ or Infamous have been underwhelming visually.
From the new gameplay footage(during the press conf) KZ made some improvements since we last saw it. I didn't get to check out the hands-on from this one yet, but I'm not very surprised, because from the very first reveal, this game was never hiding behind a convenient "it-not-gameplay-but-its-in-engine" PR wall. While I don't know if I'd call what I saw of KZ "absolutely amazing", but it's impressive enough not to be lumped with the 'others.'
Now with Infamous, I'm going to have to disagree with you guys. This is one of the games where I actually did see hand-on footage. While it still a good looking game, it wasn't any where near the quality of the supposedly "realtime" reveal trailer. Same with Drive Club. Knack, which I also saw hands-on of, isn't particularly impressive but it looks just fine for that type of game. Like KA:SF, Knack was never in danger of not hitting it's visual target because we knew from day 1 how it looked during gameplay.
To put things in perspective, I saw that
13 min gameplay footage of Bayonetta 2, and my freaking jaw hit the floor(train scene and boss fight). The point I'm making is that the hype - crated via some really "suspect" reveal trailers - that was centered around these games for their visuals completely vanished into thin air the moment I saw these games actually being played. Now, there's time between now and launch to make improvements, but currently, it is what it is.