Have multiple category queries from the URL been fixed yet?

If you have a feature request for WordPress, the best way to get it addressed is to add a ticket on Trac. Then developers can adopt the task, patch WordPress, and submit the improvements to the next version. If a Trac ticket has already been created for a particular feature, you can comment on it to weigh in and follow the subsequent discussion.

The last time I checked, there was a ticket for querying multiple terms in a taxonomy (tags, categories, or custom) at the same time: Ticket #12891.

According to the ticket, the project is scheduled to be included in WP 3.1. But we won’t know for sure until the first release candidate comes out. According to the last scope update before the feature freeze, this is going to be included in 3.1 … but it won’t be “fixed” until 3.1 is actually released.

If you want to use the feature now, you have a couple of options:

  1. You can download the actual patches from Trac and patch your WordPress installation to add the new functionality. I wouldn’t recommend this because they may or may not depend on other 3.1 improvements that aren’t included explicitly in these patches (i.e. improvements added by other tickets).
  2. Install the WordPress Beta Tester plug-in and upgrade to version 3.1-alpha. This would be the safest way to use the new feature, but still might cause problems! WordPress 3.1 isn’t considered “stable” yet and some of the features/code might (will definitely) change before the final release date. There’s no guarantee that the latest nightly build will be bug-free.