Key features which will be unavailable to Android apps running under the compatibility layer on the PlayBook and future BlackBerry devices include Android's famed battery-sucking Live Wallpaper, SIP and SIP VoIP, anything built using the Native Development Kit, apps containing only App Widgets, and apps containing more than one activity tied to the Launcher.
In addition, any packages which rely on Google Maps, in-app billing services, Android's text-to-speech engine, or the cloud-to-device messaging system will all be rendered unusable under the company's runtime system.