Yes, it is good as they talk.
First, I tested a landscape photograph.
I augmented the canvas width size, which made the image with two white and large stripes on each side.
I selected both and applied the Content Aware Fill and I gotta say... amazing.
Looks like the image was like that before.
The second test was with a 1024x1024 portrait.
Same canvas thing.
Left side had "winterish"-trees and, on the right side, an entire face.
On the left side, the Content Aware Fill worked great, it was just perfect.
However, on the face side, it was messy.
I saw chins, mouths, shoulders, eyes, all blended together.
Which means that you cannot have too much details (like a face) very near of what you want to expand.
Skies, landscapes and oceans are all good.
Nonetheless, I tested a picture of a broken boat on the sand.
I rebuilt the entire boat with this Content Aware Fill "tool".
Also, it's good for making flares, dust, birds, people and mountains disappear.
Yes, it's that good.
That's why this motherf*cking Photoshop CS5 is US$1000.
I would never pay it though.