This is great news for photographers. Firefox 3 includes color management. It's not turned on by default, but you can read how to do it on Ron Galbraith's web site. Once set up however, your calibrated images should look great on your browsing labtop or any other computer that uses this setup.
I would recommend that pro shooters show their clients how to do this, and if necessary, set it up for them in person. This should improve online photo work for all parties involved.