The leaks comment was not pointed at Apple directly but at all the manufacturers who produce parts that seem to jump at the chances to say "Hey, I'm building something for Apple and it will do this this and this.."
Yes, It's outside of Apples direct control but they don't actively discourage it either. They could insist upon nondisclosure agreements as some companies do (and yes sometimes those are a joke,) but really why would they. The speculation is good marketing and I'd find it hard to believe they don't smile just a bit every time it happens.
You are correct, it's not meant as an iphone replacement. My point in saying it is neither netbook nor iPhone was to pose the question, "exactly what kind of device is it?" It may be exactly what somebody needs.
Perhaps some context around my own situation can help to describe why myself and many are disappointed.
Personally, I've been desiring a light device that I can go into a meeting with, quickly switch between several open documents that we are reviewing without closing the other, quickly add in my own notes right on the doc and hopefully even be able to sketch a quick and dirty diagram in there with a stylus. I also need to pop up an email and open a web browser with, all without annoying the chair of my meeting with my constant clicking of a keyboard.
Thus a slate device appealed to me. The technology is really just maturing but there are solutions for the above. I held of on buying until the iPad came out because there was just enough hype to make me think I might be missing something if I didn't wait. Thus, I was disappointed. It's not a big deal. I didn't lose anything. It's certainly hasn't hurt me in any way. But since we were expressing our opinions, I was disappointed regardless of who set the expectations.
