I've been having a fun time chatting on the Unicode Email list. I think I have a plan that may get SignWriting added to Unicode sooner rather than later.
My plan breaks down into two steps. The first is to write a proposal to encode all of the ISWA 2010 symbols with 674 code points. The proposal will need to show there is a sizable community of users. It will need to prove the stability of the symbol set. It will need to define and justify all of the symbols to encode.
The proposal will need to pass through two committees. It may be quick and easy. It may get mired in revisions and rewrites for years. I'm not sure what to expect.
No small feat, but it is focused and has a reasonable chance of success.
I'd prefer that we were able to hire professionals to write the proposal for us, but unless someone knows something I don't, this proposal will be written by volunteers. Probably myself. I will be creating a new version of the ISWA HTML Reference specifically for the proposal.
This proposal will not include any of the structure or layout characters needed to actually write sign language. That will be covered by the second part of the plan: a Unicode Technical Note for the lightweight markup I am calling the "SignWriting Cartesian Markup".
There are two reasons to use a markup for layout. The first is that Unicode has already rejected layouts in the past, specifically western musical notation. The second is that Unicode would need to be convinced that the layout style proposed was the best choice. There is no reason to confuse the symbol proposal with a layout proposal.
Upon reflection, it makes sense to wait to encode the layout. With only the symbols encoded, we can apply different layout styles. We could try polar coordinates of angle and distance. We could try a tree structure where symbols relate to other symbols, rather than the center of the sign. We could try a style with predetermined symbol placement rather than give the writer precise control over symbol location.
I have already started the research needed to write the proposal. I will only be spending a small percentage of my time on the proposal at first. I'm hoping to have a proposal ready to review later this year with an official submission before the end of the year.