A lot of Android apps use ARM native code. Since x86 is not ARM, the
Market simply hides those apps to keep you from being disappointed
when they simply crash as soon as you load them.
Most games use ARM native code. This includes Angry Birds.
Many apps use ARM native code. This includes the Opera browsers.
Unless there is a free and open source ARM emulator to be included in
Android-x86, it's not going to work. And even then, the apps will run
very slow.