Currently I'm redesign one of the themes which I contribute to Drupal, Simpler. I did a lot of changes in future versions, such as more cleaner and give priority to simplicity.
The biggest problem of this redesign process is time, now my time taken to complete the project from my clients so that the time to develop my projects at Drupal.org slightly reduced. But I'll devote my free time to Drupal community, so you do not have to worry.. ya like Drupal 7 version etc. :)