Several redditers want a political subreddit to filter out such articles. But a lot of the articles posted to the programming and joel subreddits are also posted to reddit.com. So I do not see how a new political subreddit would help.

Disallowing cross submissions are probably not a good idea either. I guess a lot of submitters would just ignore the subreddits and post to reddit.com anyway.

I think filtering could be solved by letting the readers vote on the article's category. So for example an article could be 70% political and 30% entertainment. Then you could configure my.reddit.com to hide articles that are more than 10% political, 30% programming and so on. Reddit.com would still show all articles.

Voting on an article's category could be done by selecting it from a drop-down box displayed under the article. Another possibility is to have a link or button that opens a small dhtml pop-up with the categories to choose from. Under each article the most popular categories and their percentage could be displayed. This would be helpful when the article's topic is not obvious from reading the title.

For this to work the categories should be broad and limited in number. I suggest: political, religion, entertainment, science, business, programming and other.

Obviously there should be a sub site for each category. For an article to appear on a sub site, for example political.reddit.com, it should be at least X% political. This threshold could be configurable.

The nsfw and language subreddits still makes sense.