I think absolutely brief bursts of exercise are very beneficial. I'm one of those high energy people who can't sit still and I love to workout, but my schedule is also just about as packed as it could be, so there are those days when I just can't do my regular routine. However, I still walk my dogs, run up and down the stairs, or walk around the parking lot several times while food shopping. I even have an exercise plan for doing house work. So, shorter increments of 5 and 10 minutes here and there during the day add up to benefit your heart and help you burn calories.
Bursts of activity are beneficial to your health in the same sense that interval training (difficult bursts of activity alternated with moderate activity) is good for you. You will see increased fitness levels more quickly if you are consistent in making sure you total at least 30 to 60 minutes of exercise in total in each 24 hour period.
A little exercise at your dinner table never hurts. Exercise your judgement, your moderation, etc. If you do not have time for anything else - brisk walk 2 times a day for half an hour in unpolluted areas(park,lakeshore, mountain, etc.) will be sufficient for a regular guy. !Don't jog in traffic: Jogging while inhaling polluted air increases the stress on runners' hearts!
I think long workouts promote good endurance, but short, taxing, workouts can be very effective. People should adopt a healthy lifestyle that uses many different activities and workout types...long and short. I don't think we'll ever find the magic workout. Again, just my opinion.