Hi:
Since the feature is being continually developed, I believe that any updates to the documentation will be put here.
http://support.sas.com/rnd/base/datastep/dsobject/index.html
In fact, there's a note on the page that says
This feature is preproduction for SAS 9.1.3 and later, and it can change at any time. Please direct questions or comments to Daniel O’Connor.
The improved stuff won't make it into the "What's New for 9.2" documentation because this facility is still pre-production.
When this capability becomes production, then what you see out on this site will get used by the documentation people as the basis for the formal documentation. At some point, I believe the continuing changes will find their way to this web site...or a link will be posted from this site to a site with more information, if the feature undergoes radical changes.
Since this is all pre-production, it's really hard to pin down -exact- changes. If you really need to know more, then I suggest you contact Dan with questions or feedback on what you've experienced using the DATA Step Object and/or what you'd like to see. When you click on his name in the warning note, you can send email directly to him.
cynthia