I think there is a small minority of people who would want that.
Also, I have always hated using laptops. They seemed cool back when I didn't have one. Then I got one and hated it. They're heavy, they're not easy to use in a train or plane seat, they get excruciatingly hot, and they're a pain to lug around in a laptop bag, especially when you're flying and having to get one through security.
I have always used laptops as a necessary evil and as a way to get things done and still be able to be with my family, not down in my dungeon where our tower lives.
When iPad 1 came out, I still had a laptop and took it on a family vacation. We were sitting at the gate waiting to get on a plane, and I saw a guy with an iPad (this was about a week after they came out and nobody had one yet). He was casually scrolling through his e mail, looking at Facebook, looking at photos, etc. I was standing there with my laptop bag hanging on my shoulder and turning bright green with envy.
That was my "AHA!" moment. A tablet is what I have been longing for this whole time. The iPad was the answer to my prayers. I wasn't storing anything on my laptop, and I wasn't using it for anything that required all that processor and RAM. I was just using it to fill out orders for work, surf the web, and check e mail.
I think a lot of people want to get away from the traditional laptop. Doesn't mean a hybrid wouldn't sell. But I really don't think a hybrid like this follows Apple's rules of simplicity. People want tablets now, not laptops.