We've just noticed a big spike in iPlayer traffic. I think it's fairly easy to conclude that the traffic is people watching the opening ceremony of the Beijing Olympics. We are currently seeing around 600Mbps of iPlayer traffic, with the Olympics stream being roughly 430kbps per customer when you deduct off the normal volume of iPlayer traffic around 1,500 of our customers are watching the Olympic's via their broadband connections. You can see a couple of graphs showing the increase in streaming below. The first shows the data since this morning and as a comparison you can see iPlayer usage over the last 48 hours and over the last 8 days so you can see what it was like last week. 
Like the Open golf a few weeks ago it wouldn't surprise us if a significant amount of the traffic was coming from business customers watching at work rather than residential customers. Our expectation is to continue to see higher than usual volumes of iPlayer usage throughout the olympics, particularly on weekdays when people are away from their TVs at home. Dave Tomlinson Plusnet Product Team
Breaking news - Olympics streaming via iPlayer