I'm annoyed by the change. I was the DevNestSF meetup last week though at TwitterHQ and they said they didn't mention that were going towards doing this and instead praised the developer community for making them what they are.

When they surprised us with this, they claimed it was because most users didn't realize that they gave up that level of access to their account. This change allows them too, but at the cost of bad UX for mobile and native apps, while breaking all existing apps so far.

They moved the deadline back 2 weeks. That gives you less than 4 weeks to make the changes and if it's iOS, you have to get the app approved by Apple which takes 1 to 3 weeks (accounting for one possible reject and Apple being slow).

Then you have to hope that all your users upgrade right away and when they do upgrade they have to reauth everything again with the crappy experience.

These UX issues were what drove the design of xAuth in the first place durning the basic auth switch. xAuth was manually approved and was for clients and not for services that had a web side. These clients are more likely to need DM than most simple web app tools, but xAuth retroactively and going forward doesn't get DMs.

This will break TweetBot, older Seesmic clients, Twitalator, Twitterific, TweetDeck, TwitDroid, etc. Even the official Twitter client (formally Tweetie) would break because it uses xAuth but I'm sure they are hard coding exceptions for different clients.