Slow Feeds 3.1 has just been released, adding support for Feed Wrangler.
We are currently working on integrating even more feed aggregator services, as well as sync speed improvements across the board. But keep in mind that the exodus of Google Reader users might pose a challenge to the new services for the next few days, which might impact client performance.
Also, some people experienced a bug causing superfluous authentication error messages. This should be fixed with this update.