@Matthew I used to use the following [1] to generate a rss feed for the category `programming`. I think you can use it add this rss feed to the planet sympy site.
[1] https://gist.github.com/3975175 -- You received this message because you are subscribed to the Google Groups "sympy" group. To view this discussion on the web visit https://groups.google.com/d/msg/sympy/-/BaFd8axQxCoJ. To post to this group, send email to sympy@googlegroups.com. To unsubscribe from this group, send email to sympy+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/sympy?hl=en.