Macworld writes:

Even though Aperture seems to be squaring off with Adobe’s market leading Photoshop, Apple executives said the application is not meant to compete with Adobe.

“We are positioning this as an all-in-one solution,” said Rob Schoeben, Apple’s vice president of Applications Marketing. “We know photographers use Photoshop, so we integrated support into Aperture.”

This will take some market share away from Adobe so I expect that the next version of Photoshop will have some big upgrades so that it will be able to compete with the next generation of image adjustment software like Aperture and LightZone.

Apple Aperture