Isn't that what this is? I'm confused by your stance.
I also view these iCloud apps as a testing ground for Apple to continue to push the boundaries of their own skills, tools and technologies. These web apps are really well designed to the point of not feeling like they are web-based at all. Impressive.
No, actually, it isn't. There is no Apple developed OS X equivalent of "Notes". Notes is also highly restricted in what it can do as a full fledged "notebook" app. I can not insert and take pictures, I can not "scrapbook" various forms of media together to collect my thoughts, brainstorm, or plan out projects, and I can not alter pdf's and highlight/annotate important parts. Oh, but I can make grocery shopping lists, something I can do in a notebook app anyway.
Notes is exactly what it's trying to portray, a yellow notepad. What is really useful though is an actual notebook, and it's a better application of resources to go all in or not go in at all (i.e. focus on other areas).