I think all of the known issues have been addressed (See http://www.mediawiki.org/w/index.php?path=/trunk/extensions/RSS&title=Special:Code/MediaWiki/path) and all we're waiting on now is a final OK from Tim before deploying. I'm going to update the documentation on MW.org (http://www.mediawiki.org/wiki/Extension:RSS) now.

Looks like Tim did this today: http://wikitech.wikimedia.org/index.php?diff=30243&oldid=30236&diffonly=1

Currently, trying to use the extension with the code "<rss>http://blog.wikimedia.org/feed/</rss>" on wikimediafoundation.org throws an error: Failed to load RSS feed from http://blog.wikimedia.org/feed/: There was a problem during the HTTP request: 403 Forbidden

Roan thinks the proxy (url-downloader.wikimedia.org) might not be passing the user-agent.

No, the problem is that that proxy is configured to deny requests to hosts on the internal network:

acl to-wikimedia dst 208.80.152.0/22
acl to-wikimedia dst 91.198.174.0/24
acl to-wikimedia dst 10.0.0.0/16
...
http_access deny to-wikimedia

If blog.wikimedia.org is the only host we need to access, then I can just disable the proxy.

(In reply to comment #3)

If blog.wikimedia.org is the only host we need to access, then I can just
disable the proxy.

The current use-case is for blog.wikimedia.org only (http://wikimediafoundation.org/wiki/Template:Blogbox). It's not unreasonable to think the extension might be used with other domains/subdomains, though. For example, techblog.wikimedia.org or an outside FOSS blog or an outside personal blog of a staffer. If it's possible to have the extension work with any RSS feed, that'd be best.

I've disabled the proxy.

Okay, this is working now: http://wikimediafoundation.org/w/index.php?title=Template:Blogbox&oldid=52180

I think this bug is resolved as "fixed" now, unless there is further proxy work you think needs done.