Twitter for Android has been updated to version 2.0 and it's quite a major change. In fact, it looks like a different app altogether.
Cosmetically, Twitter have done away with the official shade of blue and replaced it with an altogether darker looking skin, more akin to Tweetdeck. The 't' icon, used before for notifications and the app shortcut, has been exchanged for the Twitter bird logo.
The old home screen, with links to tweets, replies, lists, retweets, DMs and profile, has been removed. Now the you are taken straight to your timeline, with links to replies, DMs and lists in a toolbar at the top of the screen, just like many other Twitter apps. I liked the old homepage, but I know lots of people didn't.

There is now an option in the settings to turn off the, much derided, sound effects. There is no option to choose a URL shortening service anymore.
The previous version had a dedicated retweet page with links to retweets by you, by others and by others of you. This has now been removed and there is just a list of retweets by others, tucked away under the lists menu. Retweets of your own tweets now show up under the replies tab.
The geotag on/off toggle switch is still there when you compose a tweet, but the icon is now more subtle and makes it less obvious whether you are tweeting with it on or off.
The timeline, reply & DM icons don't have a count anymore, just a glowing blue disc next to them when there are new items.
The tweet button, which now highlights blue when you type in the text box, has been moved to the top right. A strange place for a submit button.
Twitpic photo previews are now much larger, almost removing any incentive to click through to the full image.
The new conversation view of tweets is good. It is clear and quick to load.
Typing '@' and a letter in the tweetbox will give you a drop down list of usernames. It doesn't seem to be everybody though, there is some kind of filtering going on.
Overall the app feels faster and more responsive. It has obviously been tweaked a lot under the hood. Still no 'move to SD card' option, but maybe part of the bug fixes in this new version may stop it growing uncontrollably and eating up phone storage space. Also, there seems to be no sign of the, long promised, instant notification of replies.
[Posted by email via Posterous]