every one I’ve looked at hasn’t been updated for many years.
These are all listed by descending order of date, if that helps:
http://wordpress.org/themes/browse/new/
You can also search by specific characteristics: http://wordpress.org/themes/tag-filter/
If there is an advanced search operator within the Them Directory that will allow you to return themes published within a specific date range, I’m not aware of it (or just haven’t noticed).
You can, however, use Google advanced search operators to narrow the scope of themes to those (possibly) published/updated within just the last year, if that helps at all.
Example: https://www.google.com/#q=site:wordpress.org/themes&tbs=qdr:y
Thanks for taking the time to help, Clayton. I hadn’t thought of filtering by date.