From ZDNet UK
Exactly what I thought was the cause of the problem a number of people had yesterday when trying to get an update. However, I'm surprised at the transfer rate of 50GB/s.Microsoft's patching site experienced record levels of traffic as million of people attempted to patch their PCs
The crush of millions of Windows users trying to patch their computers overwhelmed Microsoft's update service for several hours after new security fixes were made available, the software giant acknowledged on Wednesday.
Immediately after Tuesday's release of four patches that fixed a score of flaws in the company's operating system, traffic to Microsoft's Windows Update site spiked higher than seen during any previous update, reaching a sustained download rate of more then 50GB per second. Past patches have resulted in two million people visiting Microsoft's Windows Update site every hour to download fixes. This time, between three million and four million users came to the site.