Slightly heavier (though not so much that you'd notice),
Lots of folk complaining that the resolution of the rear camera could be better (though I've yet to see anyone use their iPad like a camera). Lots of folk complaining that it hasn't got the full Siri experience (I wasn't expecting it to).
When it arrives at the local Apple Store I'll take a look, but I don't think there's enough there to upgrade this time round.
Having said that, once the developers start to churn out stuff that looks good on the Retina screen then I'll probably cave in.
The problem Apple had here was that there was way too much hype for an incremental upgrade. A few hours before the event, there was insane rumour that it was going to include a new revolutionary haptic display and would be made of liquid metal!
Still, with a little clever press manipulation, the CEOs of the companies involved managed to hike their share price for few hours.