But I've been putting these tools to good use - especially Sketchbook Pro. What a well-designed, agile program for making digital art. I think this could quickly replace Photoshop in my illustration toolbox. Like Photoshop, you can work in layers, choose a range of brushes (not as extensive, admittedly, but the layout is much easier), and even save files as .PSD, if you want to move a document into Photoshop for final touches.
But Sketchbook Pro has some neat things that Photoshop doesn't seem to (at least, in CS3, which is rather outdated now, I realize). If you'd like something to be symmetrical, there's a mirror effect you can choose where you draw/paint one side of the image, and it automatically copies what you're doing on the other side. Saves a lot of time.
This program is also a lightweight and loads up fast. It doesn't bog down my computer, allowing me to run other programs without any issues.
I've only been playing with it for a few days, so I'm sure there will be some drawbacks. Doesn't seem like you can make your own brushes, for instance. But, so far, at least for the kind of digital art I'm making, this software floats my artistic boat.