I really hope it isn't built in Flash, the Nike+ website is built in Flash and is pretty terrible, it's slow and buggy.
Agreed. I remember when I was training for a triathlon, and before I had my Garmin I used Nike+. Did not particularly like the website. It has definitely grown and improved over the years, but using Strava/Garmin Connect/DailyMile is so much better now.
I really like the payout of the site. Very impressive for it to be V1