Twitter recently changed the way they authenticate, moving from basic authentication to OAuth, a move which broke a number of third party apps, not the least of which is HTC’s built in one. If you have an HTC phone with their custom Sense UI, you’ve no doubt encountered Peep, their included Twitter client. Well, now it’s broken. As of this morning, it’ll just tell you that you’ve entered incorrect username or password.
Twitter announced these changes in December in order to allow everyone ample time to update their apps. I guess HTC completely ignored this, and just let the app sit there.
This is why I don’t trust bundled software.

It’s not just a third party app issue; The Twitter for Android app ceased to function properly as of yesterday, as well. It cannot receive tweets from the server, nor can HTC Peep. Looks like Twitter didn’t bother letting anyone know about the back end changes.
Thats odd. Other than the wonky refreshes/reloads for the widget since the last update, I haven’t had any issues with Twitter for Android :S