I have been using the NBC Olympic App on my iPad today - and I must say I am pretty happy with it.
You can find and watch the events you are interested in.
Just been watching the Womens Super-G - glad I don't have to ski that start
There are still ads - but it is way better than the NBC TV coverage.
Average download speed over 10 minutes is about 2 Mbps and picture quality OK on the iPad
(note I found airplay to the TV more problematic as you no longer seem to be able to pause events and restart which works fine on the iPad)