Twitter gets a performance upgrade
Twitter has done a bit of work to improve the overall performance of their site. So you shouldn't see much more of their "fail whale".
Their upgrade moves rendering back to the Twitter servers which has allowed them to drop page load times to 1/5th of what they previously were.
The Twitter blog goes into further technical details on how they intend to speed up performance on the site. They also describe how they will remove the "hashbang" (#!) from twitter.com URLs.
While these improves are being rolled out there has been no word of when they will be fully implemented.
Source: Twitter.com Blog