I hear you, mate. The CoreImage filterfactory is a problem. Everyone speculated that CoreImage would doom Photoshop. So - where is it? I guess it's not just that which will topple photoshop. It's going to require something a little more deep. It's going to require some effort in putting together a painting interface.
I want a paint program that does vectors. Even if they're on different layers. Some sort of scaling for bitmaps. And good knockout support.
Let's face it, it will have to compete against Photoshop PLUS plug-ins. I used to really like Macromedia xRes...