According to Peter Edberg, an Apple engineer, in a 10/25/98 posting to the H-Asia Mailing List...
1. Apple is not "abandoning" WorldScript in future OS releases, nor is it "pushing it aside" in favor of Unicode.
2. One direction with WorldScript is to integrate more and more of its technology into the basic system, eliminating the need for separate files in the Extensions folder. The just-released Mac OS 8.5, for example, made several advances in this integration process. It is possible, for example, that a future release will further this process by eliminating the need to have separate "WorldScript" files in the Extensions folder. This does not mean that we are eliminating WorldScript capability.
3. Another direction with WorldScript is to provide more of its capabilities for free. Mac OS 8.5 includes an optional install for Multilingual Internet Access. This provides a subset of the language kit capability (e.g. no input methods) for Chinese (traditional & simplified), Japanese, Korean, Arabic, Hebrew, Devanagari, Gurmukhi, and Gujarati; the intent is to enable Internet browsing in languages that use these scripts.
4. Before Mac OS 8.5, the primary support for Unicode in the Mac OS was via the Text Encoding Converter, which permitted applications to convert text among various encodings: Unicode, the WorldScript encodings, and other encodings used on the Internet. The Office 98 applications, for example, store text internally as Unicode, but convert to WorldScript encodings for display and (normally) for saving text to a file (but note the Save As... option to save files in Unicode).
5. Mac OS 8.5 introduced capabilities for Unicode input and for drawing of Unicode text; some applications will use these capbilities instead of using the corresponding WorldScript functionality. Future versions of the Mac OS will introduce additional support for Unicode.
6. Mac OS X, which is expected in a year or so, has been described as a merger of the Mac OS and the Rhapsody system (based on technology from NeXT). The Rhapsody system already uses Unicode text throughout. Again, however, this does not mean that Mac OS WorldScript goes away. In Mac OS X, the Rhapsody environment and the Mac OS environment coexist as equal partners (along with Java), both running on top of a modern kernel, and sharing a common user interface. You will be able to run Rhapsody applications that use Unicode, Mac OS applications that use WorldScript, Mac OS applications that use Unicode, etc. Mac OS applications may need to be updated to run in this environment, but they don't need to stop using WorldScript.