I don't know what others do, but I train with intervals at speed, including sprints. I think as with other sports, you get a certain amount of benefit out of going for distance at medium heart rates, but another kind of benefit altogether in adding speedwork and sprints. I swim at least once a week with the Master's team, and that makes sure I do some hard interval work in the pool during the week.

The last Master's workout (Main set) I did was:

5 x 100 @ 1:50 interval
4 x 25 sprint all out @:30
5 x 100 @1:45
4 x 25 sprint @ :35
5 x 100 @ 1:35
4 x 25 sprint @40
5 x 100 @1:30

The 100s were at 1:20 pace, 25's trying to hit :15 or under.

BTW, that's the exact opposite of what I thought you were going to say, but it certainly sounds good. Maybe a little speed work is what the doctor ordered, especially since it seems like I'll be off my feet for at least a week or so.

Your profile is the same as mine (Olympic distance, intermediate, and swim as favorite leg). I like to keep my swims less than 2000 yards total, and that is because I have to focus on getting my bike up to a level on par with my swim and run. I do three workouts a week: 1 day for sprints/drills (1x400, 2x200, 4x100, 8x50, 12x25), One day of 3x500, and one day 1x1500. The sprints/drills I do at race pace for the 400 and 200, and 100% for 100's and shorter (heart rate gets way high but only for about 15-20 minutes). The 3x500 I do at race pace. The 1x1500 is a bit off race pace, and I use it mainly to make my body remember what a 1500yd swim is like. My race pace is about 1:35 right now, and I never feel overtrained with this workout routine, and I feel like I'm making gains (I just started putting in consistent workouts in the pool again). I don't do kicks or pulls because I like to save my legs for the bike and run workouts (practice the way you play / train the way you fight). These are short and sweet swims by design, so they might not fit your current situation, but could help when you get back to biking/running more.

Concerning your run, I think swimming always helps my running effort. If you hold your breath for a couple of strokes off the push from the wall, the hypoxic (?) affect really helps your body learn how to work without a lot of oxygen. If you're doing it right, you'll feel an incredible burn throughout your body, especially if you're going at a hard pace.....I love that feeling!

+1 Also, kicking is beneficial to biking and running because it works all of the supporting muscles from your hips down to your toes, and stretches and strengthens your entire leg support system. I personally believe that it helps in injury prevention in biking/running. Also, many triathletes do not kick efficiently, mistakenly believing that they don't need to kick since they're wearing a wetsuit in a race. An efficient kick is necessary for proper form and achieving a powerful stroke.