Correct me if I'm wrong. What I think I have seen in the multiple threads on this subject has been along the lines of :
"if you don't like it fix it yourself"
"to difficult to maintain multiple themes"
"give us a picture of what you want"
"no promises to implement any other themes"

even what I've read in the minimalist theme thread is that andrewblack is working on making a dark minimalist theme, but is unsure if it will be used even if he creates it (unless I've missed recent news).

It also appears that there are a couple different places where themes can be tested/modified? maemo.org SVN, a forum sandbox?

At this stage, I certainly wouldn't want to put a lot of effort into a theme if there is no guarantee it will be used.

I haven't seen anywhere (and I may be wrong) where anyone (with the power) has said something like:
"make a theme and/or get some community buy in for it and we *will* add it as an option."
Plus there seems to be multiple routes: maemo.org svn, sandbox, picture, css editing, etc.

Would some authority like to make a decision as to what process should be followed and confirm that a theme once created would be used?

Again, I apologize if I missed any of this somewhere in the multiple threads.