I expect you'll have a mix, with some consumers saying it doesn't "look" any different from Vista, and others very happy with it seeming snappy and stable. Given it doesn't "look" different, I suppose you could even have some people griping why they had to pay extra to get it.
But the big thing is ultimately going to be if it's adopted by large businesses (and government). Most probably won't bite right away, but barring any huge disaster within the first 6 months or so, you'll likely see some start moving to it and yes, I'd expect it to boost Microsoft's image.
Don't know that it will significantly chip away at the Apple markets in academia and entertainment industry, but I don't think they'll lose ground, either. If anything, if they provide good pricing to students, you could see more move over to Windows 7.