ACPI test driver version 1.0.17 has been released (10/16/2005) on the eComStation Betazone. Advanced Configuration and Power Interface (ACPI) is a replacement for APM, PnP, and related hardware features. Apparently a future version of XWorkplace will support shutting down via ACPI.
http://betazone.ecomstation.com/
Source: OS/2 Warp News and Rumors