Also, be sure to watch each other for signs of hypothermia. Though you may think it's just a cold-weather threat, it's also a cool-weather-plus-wet issue. I've seen hiking companions (and myself) start to show signs of this during a day in the rain. Even with good rain gear, a continuous rain is going to get you wet. In moderately cool temperatures (55 would do), or just a light, cool breeze, you'll chill quickly.

You need to read up on it. I've never had experience with more than the early signs (slightly slurred speech, slowed or clumsy walking, dulled thought processes, shivering while walking); we always watched each other, and someone said "We're done for today" when one of us starting acting as though the edge was no longer there. We'd get the victim's tent up first, get him into dry clothes and into his sleeping bag, and start some hot water for cocoa or bouillion. Fortunately, the victim was still with it enough to know he needed to cooperate, and the problem was always quickly resolved; an hour or so later, and all was well. I'm sure we occasionally stopped before hypothermia had begun, but we all preferred, by mutual agreement, that safe was better than sorry.

Be sure to take a set of dry clothes (medium or expedition weight longjohns and some socks would do) to wear in camp - keep them in a waterproof bag (Ziploc works well) when they're in your pack. Don't even think of wearing them on the trail; change back into your trail clothes, even if they're a little wet. (If they're a lot wet, it's time to think about using one of those bailout points.)

Also consider taking some extra food (a pack of ramen noodles, maybe some extra granola bars or candy) and beverages for that quick jolt of warmth. Also, if you usually eat a cold breakfast and lunch (like I do) consider cooking those meals, also. Of course, you'll also want to bring extra stove fuel. You might also want to bring a lightweight 8x10 tarp to pitch as a kitchen shelter in camp, or a shelter for your lunchtime stop.

Don't take this for a comprehensive lesson on hypothermia; it's not. My experience is limited to the very early onset - be sure you've read up on later stages, too. (My guess is that Midnight Sun might be an excellent source of information - you out there, MNS?)