The performance of gpodder.net has been pretty bad for quite a while, and we've been constantly working on improvements.
One part of this effort was the migration of the gpodder.net codebase from a MySQL backend to CouchDB. As of today, this migration is finished and gpodder.net has all its data in a CouchDB database. While this won't be the final solution to all (performance) problems, it should at least be a slight improvement, with lots of potential to optimize and scale.
The next step will probably be some new servers, but we're currently negotiating the deal. I hope I can reveal more information in a few weeks.
Apart from performance improvements there should now be also more time to work on new features. If you have some idea that you'd like to see in gpodder.net, let us know through Get Satisfaction or the bugtracker.