In the weeks leading up to the launch of CS5 there were several videos available on YouTube showing the new Content-Aware Fill feature in operation, being used to seamlessly remove unwanted objects from photos or fill in missing background areas. There's no question that Content-Aware Fill is an amazing feature, and playing with it is a lot of fun, but in actual use it's not as useful as you might imagine. Those demonstration videos were very carefully contrived to show the feature at its best, but in the real world the results are often disappointing. It's very good at the easy stuff like removing a small blemish from a plain or random-textured background, in other words things that are easy enough to do manually using the clone stamp or spot healing brush, but larger objects or more detailed backgrounds cause problems. If you look closely at the example below you'll see that there is still a visible outline where the texture of the sea doesn't quite match up. On the plus side though it is a lot quicker than painstakingly cloning out unwanted details.
Another impressive looking feature is the Puppet Warp function, which was also previewed in demo videos. It allows 2D objects to be manipulated and re-shaped, and even overlapped. For all its technical cleverness this too is only likely to be useful under very specific circumstances, because the object to be warped first has to be carefully selected and cut out into a separate layer, and the background filled in. It might be more useful for graphic designers than for photographers. It's very clumsy and awkward to use, and causes all sorts of unwanted distortions, so it's really not suitable for anything that has fixed proportions, such as human figures.
The Intelligent Selection technology on the other hand is a massively useful feature, and arguably the highlight of the new version. The Refine Edge dialogue window allows you to customise the edge selection parameters, but more importantly it can automatically select around fuzzy edges, something that is almost impossible using conventional selection tools. This makes it incredibly easy to select around the edges of a model's hair, something that has always been a major problem. The Smart Radius function accomplishes in seconds what would have taken hours in previous versions, and does a much better job of it. There is a special tool included in the Refine Edge dialogue to manually apply the effect to specific areas, useful for shots with a mixture of hard and fuzzy edges. Anyone who regularly photographs models will love this feature.