The admin-console has a summary screen showing the general information about the AS server and configuration.
General Properties
Name: JBoss AS 5 (default)
Version: 2.0.0-alpha-4
Description: JBoss Application Server (AS)

The version information is showing the version of the bootstrap implementation:
org.jboss.bootstrap.impl.base: 2.0.0-alpha-4

The way the version information is obtained by EMBJOPR is:

ManagedComponent serverConfigComponent =
ManagedComponentUtils.getSingletonManagedComponent(managementView,
new ComponentType("MCBean", "ServerConfig"));
String version = (String)
ManagedComponentUtils.getSimplePropertyValue(serverConfigComponent,
"specificationVersion");