It's a much higher resolution. The applications can scale, but they won't really take advantage of it.
The resolution issue is one of the reasons analysts are recommending iPad Minis over lower-priced, higher-res Android tablets. Since the iPad mini uses the same resolution as the iPad 2, a ton of apps have been built to support it. Since Android apps are a mixed resolution bag, you get a lot of apps that aren't designed for larger screens/resolutions. They'll stretch to fit, but they won't look nearly as good as if they were natively designed for them.