Twitter engineer Dustin Diaz tweeted this evening "Turns out #NewTwitter has some major slowness due to upgrading from jQuery 1.4.2 to 1.4.4 - We will be downgrading." According to Diaz, users have been complaining for the past couple weeks that the service has been slow.

Diaz provided more details via Twitter for those curious about the details. Diaz's comments might prove useful to others working with JQuery.