CEO Dick Costolo unveiled the new look for Twitter on the Today Show this morning. Fortunately the overall dimensions haven’t changed and the design modifications are occurring only within the main tweet section so those of us with custom backgrounds won’t need to scramble to fix things again, but they have added a new large header graphic to the top of the page, a la Facebook.

Personally I think it’s poorly designed, takes up way too much real estate (especially on the mobile app) and I really don’t like the way they’ve put our avatar in the center of the graphic with our name and bio in white text which means that Twitter darkens the photo so the text shows up even on light backgrounds, giving it a muddy look. We’re going to start seeing a lot of really ugly and hard to read Twitter pages soon.
You can switch to the new layout now if you want: settings/design/change header
According to an email I got from Twitter a few minutes ago, everyone will be switched to the new look in November and if you haven’t uploaded a header image they’ll just put an ugly grey box there.