The first hack at the optionmatrix datatype has been released. To keep up on changes etc. you can also take a look at https://github.com/leidentech/optionmatrix.git
Keep in mind this is beta code.
The first release isn't going to be useful for most people since it's really only able to feed form results to a custom module - that's what I built it for and that's how I use it. I could add a module to dump the post variables as an example but it seems to be to much overhead for a datatype - but, I'll add it if people really want it.
It wasn't until I was packaging this for release that I realized that for most people it won't be useable since it's not really usable out of the box. What they'll really want is the results to go to collected info. Which, of course, I never looked into before today. But, I'll try and work it into my busy schedule in the next week(s).
There are a couple of things that still have to happen. Take a look at the doc/TODO.txt file for more known bugs^H^H^H^Hfeatures.
Leave a comment in the forums if you'd like to see something else added (or see something bone-headed that I did in the code) - git pull requests are always welcome.