I certainly would welcome and encourage WRI to produce a new public version of Workbench.
However, there are two applications of Workbench: 1) Documentation; 2) Everything else such as debugging, integrating C code, multi-person projects etc. It is only the documentation that interests me. Even though I work on moderate size applications and sometimes with a few other people, I don't find a need for these extra features. I find it easy enough to debug just by inserting temporary Print statements in routines. I don't find any need for an auxiliary IDE. Mathematica is a fairly sophisticated IDE itself. I'm sure this aspect of Workbench is important for internal Wolfram work what with all the C code, and there may be a few enterprise level customers who would make good use of it. Most users, doing math and science, don't really need this aspect of Workbench.
Documentation is a different matter. It is a part of preserving your work and making it accessible to others. Documentation is an optional but usual part of an application. An application is the best way to communicate your work to others. Papers in the form of Wolfram notebooks can be supported by applications and may be included within an application. They are orders of magnitude better than current publication practice. It is rather a shame that all the publications of papers on arXiv.org aren't accompanied by Mathematica paper/applications. - instead of none of them.
I don't know if user documentation has to be tied to Workbench. Perhaps a separate documentation facility could be provided. It really should be available to ALL Mathematica users. An earlier form of documentation was available to all in Version 5. Somehow this vision of Mathematica as a development AND communication medium got lost. Everything is there except Documentation. Otherwise writing applications is really easy.
As for communicating with people who don't have Mathematica? Tell them to get Mathematica; it works and it's worth it.