Painter 8 is really nice. It brings the interface even closer to Photoshop's and fixes some nice things like bringing the Painter 6 watercolor brushes back as a seperate set.
Canvas is a nice little 'do-it-all' app, but has virtually no usage in the professional industry. It's near impossible finding a printer that takes canvas files natively. So in the end you'd still be converting to a bitmap file format which kind of defeats the point.
Another nice little program you guys might wanna check out is Expression (
http://www.creaturehouse.com/expression3.htm). It's basically a cross between Painter and Illustrator.