Earlier this month, Twitter officially unveiled its new API. After months of talking about talking about new restrictions for third party developers, the network finally anted up and put things in specific terms. The short of it: Developers have until March 5 to comply with the rules – which more or less heavily restrict the creation or use of anything duplicating Twitter’s core function – or else.

No surprises here. The blog post heard round the tech world late last month put everyone on warning, announcing that services that use the Twitter API to mimic or recreate the service (which, for the record, is a very vague statement and a thin line… a thin line which Twitter will interpret as it sees fit) are on the outs. And the reason why is incredibly clear: Twitter wants eyeballs on its site because it’s a media company now with partnerships and big ad deals. And if users are looking at a third party client, all that money will slip away. Of course, if Twitter would update its proprietary app with the features we’re being driven to outside services for… but that’s a whole other issue, and one that still puts third party developers out to pasture.

“It’s not surprising, it’s what we all expected,” Bottlenose creator and CEO Nova Spivack told me when Twitter officially announced the new Rest API. And it isn’t, and neither are the limitations for alternative Twitter clients but now it’s time we take a look at the carnage being left in Twitter’s wake thus far.

First up, big changes for services like YFrog and Twitpic, which take and post pictures to Twitter, are being run out. According to Buzzfeed, Twitter reached out to tell developers this was coming. (Which is something of an unprecedented move: When Twitter first introduced its own photo sharing feature, third parties were given no warning). Twitter will be removing support for outside photo-sharing apps, a change likely coming in the next issued updates – so  you can say goodbye to most of the photo-sharing services on this list. (For the record, Posterous is owned by Twitter).

“Because of twitter’s actions against devs the past year we kind of thought this was going to happen at some point, and Twitter did reach out to us to let us know which I really appreciate,” TwitPic founder Noah Everett tells me. “I understand why they are going this route since they are under pressure to make ad dollars; however, obviously we do wish they wouldn’t pull choices away from their users. The majority of our uploads come from other sources, so this doesn’t affect us much, and we’re still going forward strong.”

It might not be surprising that this is happening; it lines up with Twitter’s new agenda and photo sharing spells big traffic. But I have to question how core this is to the Twitter experience – the proprietary platform didn’t even introduce its own photo feature until last year. It definitely wasn’t part of the original Twitter core function, and it’s remained so silent about its evolutionary focus that claiming this to be a key cog of the Twitter machine seems like a stretch.

This is a big switch-up that immediately will impact users, but here are a few other specifics suffering from the Twitter ecosystem changes:

  • RSS, XML, and Atom support is being ended. This is more the end of function rather than feature, and will be a developer-facing issue rather than something that impacts end users, but it’s worth mentioning.
  • Tweetbot is having yet more problems with its beta because of the Twitter limitations. Basically anyone who is trying to grab the client after already having authorized it might be out in the cold until the final version is available. You can check out this blog post for troubleshooting help, but it’s possible you just have to wait.
  • Big, popular sites have lost access – we’ve already covered this, but it’s still sort of a head-shaking move on Twitter’s part: Tumblr, Instagram, and LinkedIn can no longer use the site to find friends or in LinkedIn’s case send tweets to its own platform.
  • Twythm CEO Ben Thomson recently wrote a guest post about how he had to rewrite much of how his application functions – the bigger picture here being that Twythm, a service that allows you to post what you’re listening to, something Twitter has no foot in, changes the way tweet timelines are displayed, so it’s on the outs. It’s just an example of how the new rules can be interpreted and hurt outside applications.

I don’t want to add to the Twitter hate-fest that’s been brewing since the company started making these moves, but it’s important to reflect on what’s happening to individual services right now, and to look at how it could affect future ones. Remember how Twitter said it was going to introduce its own fully-featured analytics client? Does that mean that applications currently doing this – of which there are many – should start watching their backs?

It’s questions like this we’ll have to keep asking as Twitter continues to evolve and interpret its own function.