The new online score database is filling up nicely. Right now more than 93% of the levels are listed as solved.
The latest version of Sokoban uploads scores silently in the background at a slow rate.
Check out a list of still unsolved levels here http://www.sourcecode.se/sokoban/unsolved.php.
That link takes us right here to this thread.
I had to copy/paste the URL into my browser to get to the correct page.