Twitter isn’t known for making frequent design alterations to the site nor anything particularly major when they do. That said, over recent weeks the site had made a number of design refinements, the most significant being the homepage redesign.
One noticeable area that didn’t see any sign of change was the sign up/login form that followed the homepage. Now, although Twitter has still yet to do anything drastic, the background to the sign-up/login form has been replaced, along with the default Twitter background once you’ve created your account. The following/followers/tweets figures have also been given a crisper text formatting – helvetica I believe?
Default avatars have also been changed to a slightly more modern and colorful range. And the 404 page and suspended acccounts pages have also been redesigned completely.