Loving it! I was just going through our webhook-initiated payment resque job last night to rewrite some of the legacy webhook stuff we had in place (and handle failed charges, which we never did until I recently filtered orders by status and saw a handful)

One tiny nitpick is that this field is too small IMO: http://dl.dropbox.com/u/186198/Screenshots/p5uf.png

Also nitpicky, I would like to have the test charge.failed webhook include a fake description param.