A few months ago I started using Safari for most of my browsing, because I love trackpad gestures and I'm a sucker for smooth animations. However, if there's one thing that Safari gets spectacularly wrong, it's dealing with XML. As far as I know, in Safari 6.x there is no way to display raw XML, the damn browser will always try to launch an external feedreader, and even selecting which feedreader requires industrious hacking that I'd rather avoid. This is particularly annoying when some memory-hungry, battery-burning giant application hijacks this process: in my case, VmWare Fusion will always try to launch one of my images, which is just terrible.
To cut the story short, I wrote a small extension to prevent this horrible process. When I want to have a look at an XML file, I right-click on the link and select "Show me that feed". The result is a slightly-formatted view of the file, in a new tab.
You can download the ShowMeThatFeed Safari extension on BitBucket.
I haven't been a web-plumber for more than 10 years now, so I'm sure it can be dramatically improved -- the formatting in particular is implemented with regexes (argh). Please feel free to fork the BitBucket repository for ShowMeThatFeed, pull requests are very welcome.
UPDATE: Apologies, I've pushed quite a few updates (included some buggy ones!) in the last few hours, but now it should work fine.