We saw 5x normal tweets-per-second and about 4x tweets-per-minute as this chart illustrates. Overall, Twitter sailed smoothly through the inauguration but at the peak, some folks did experience a 2-5 minute delay receiving updates. [Source]
According to Hitwise: UK Internet traffic to the site has increased 10-fold over past last 12 months. For the week ending 17/01/09 www.twitter.com ranked as the 291st most visited website in the UK, up from a ranking of 2,953 for the week ending 19/01/08. UK Internet traffic to the website has increased by 974% over this period. TechCrunch also mention famous Twitter users and the impact that they have on the site. This friday should be interesting as Jonathan Ross on his comeback show is set to discuss Twitter with fellow Twitterer Stephen Fry. Will they be able to convince Tom Cruise to start tweeting, that would be interesting to follow! :)
Is Twitter on the verge of mainstream adoption?