ASUS is like everyone else unsure about what direction the market is moving in and betting on two horses. The difference is really between running a lightweight but limited web-focused operating system like the iPhone OS or Android vs. running heavyweight operating systems that run advanced software applications like Windows 7 and Mac OSX do.
The question is what the people that buy these things want. Just browsing and running basic applications from the app stores, or actually doing advanced work.
Due to the nature of Windows 7, it’s to expect that ASUS will come with a higher-spec device than the Eee Pad.