I do the same as the quoted excerpt above.

For feet, I wear layers of wool socks and sandals. I have sealskinz to put over socks -- the key is to get them larger, so you can layer comfortably.

I have a pair of waterproof mitts that go over gloves or not. They are big enough to accommodate anything I need to keep my hands warm so I will also wear them when it's really cold since they break the wind.

If you are like me, you are going to sweat somewhat. I always prefer warm sweat to cold rain, but even warm sweat will get you cold eventually. As AdamDZ points out, get a jacket with pit zips. These are key to keeping the upper body dry from rain while providing ventilation to keep sweat down.

If you haven't got a place to dry things out before your ride home, take extra to wear after work. This is the beauty of sandals, by the way -- it doesn't matter if they are not dry (though they likely will be).