Are rusty disc brake pads a worry? I'm the fool who didn't wash the snow off his bike - it's a rusty mess.

I've just taken apart the front disc brake as it was rubbing. I think that was more to do with the disc being bent, but as I was doing it, I found the disc brake pads (?) are pretty rusty. This is what they look like:



Should this concern me at all? Can I clean them up, or should I replace them? Or are they fine just to be left?
Rust on the surfaces of the pads &amp; disc could cause extra wear &amp; noise, or if bad enough reduce the effectiveness of the brakes. If there is enough present that you can see residue on your finger after rubbing the surface, I would suggest cleaning with a stiff bristled brush or a kitchen scrubber &amp; isopropyl alcohol (some people have recommended automotive brake cleaner too). There will probably still be some rust coloring on the pad, but it shouldn't be enough to cause a problem.
After cleaning, you should really inspect the metal around the pad too to make sure it is not corroded to the point that it may not fit the caliper right or could possibly break.