UPDATED – LATEST: Here is twitters official response!
and Here is mashables take on the situation!
UPDATE: Twitter staff has confirmed it is a twitter related error and it will restore shortly, so no worries!! Your account is fine! 🙂
So I just noticed that a ton of people (including me @andysowards) Have had their profiles avatar and background overwritten with default twitter avatars, and backgrounds, This looks like a messup from the twitter team updating the ‘default’ stuff with new options.
Anyone that knows whats going on shed some light below in the comments and I will update this post as soon as we know whats going on!
In the meantime, you have probably noticed the design tweaks twitter has been working on, so its good that they are updating!
Thanks everyone!