Hi Patrick,
I will answer your question as follows:
1. We cannot comment on future releases in this forum but we can invite you to take a look at our 2011 beta release at http://beta.autodesk.com/ to see what we are working on and new functions
2. Yes you can add new objects based on what is already in the catalog with copy and paste method. Once copied you can change the dimensional and decsriptive information including the field "Iso Symbol Definition" where you can name the ISOGEN class and SKEY.
3. Its very easy to change Size, spec, linenumber, insulation, etc. just by pick the objects then invoking AutoCAD's properties UI and changing the required fields like Spec.
4. Our plan will be to follow AutoCAD's release schedule.
Mike G (Autodesk)
Michael Gulnac
Technical Specialist
Organization
Autodesk, Inc.