Is it me, or do you have to be hardcore to tell the difference btwn 6 and 7? Most hobbyists are probably still good with 6. I use both, 6 at work, 7 at home.
7 has, imo, a better looking toolset (they have color! and have some dimension!) and an image browser, not to mention a different brush customization (i prefer 6 over 7), and a couple other small things. After reading about Photoshop 8, I can honestly say that it'll be worth the money. Text on path, definitely a plus. As it was a pain the @$$ to change the flow of text without doing something really ridiculous with the rasterized text layer. Also the "filter layers" will be a great idea. I remember a conversation I had a couple months back with a friend about what I would like to see in Photoshop. I had said that having just a filter on a layer on its own, would be a great implementation. And lo-and-behold, the great Adobe god has answered my prayers :)