When Twitter bought Atebits in April, a lot of us were excited about the possibilities. After all, Atebits (aka Loren Brichter) was the company behind Tweetie, the best iPhone Twitter client and arguably the best desktop Twitter client as well (though Mac-only). Developers, however, were not as enthusiastic. Many wondered what it meant for the state of the Twitter third-party ecosystem.

So far, the results of the acquisition seem to have worked out well for everyone. Tweetie for the iPhone was reborn as Twitter for iPhone. And while it’s largely the same, it has added a few bells and whistles thanks to the tighter Twitter integration. But other third-party clients, such as Seesmic and TweetDeck, have continued to thrive as well.

But make no mistakes, Twitter is still working on the next killer client.

As Brichter tweeted out today, “Why yes, it is hard building THE MOST AMAZING CLIENT YOU’VE NEVER SEEN when the API is exploding.” The CAPS are all him.

It’s not clear if this is a new version of Twitter for iPhone or if it’s the long in-the-works next version of Tweetie for Mac (which will undoubtedly be called Twitter for Mac now) — though I’d bet on the latter. Or it could be a native version of the Twitter app for the iPad — something which is also known to be in the works.

A few tweets later, Brichter responded to a question about Twitter for iPad. Someone asked him, “Will the iPad version be like tweetie for iPhone but bigger?” Brichter’s response: “Nope.” If Twitter for iPad is going to be more than a upscaled version of Twitter for iPhone, perhaps that is the “amazing client” Brichter is referring to.

Of course, Brichter sent that tweet from “Tweetie for Mac” — if that means anything. Interestingly enough, “Tweetie for Mac” now links back to (it used to link to the Atebits page).

Regardless of what this new killer client coming out of Twitter is, the community must appreciate the fact that Twitter’s own internal projects are subject to the same API limits as everyone else. Recently, this has become a big issue as usage is exploding.

Earlier this year, Twitter’s Alex Payne (who has since left the company) tweeted about testing some new features that may make users “not want to use a desktop client.” This had many in the Twitter developer ecosystem freaking out. But really, it’s somewhat silly to expect Twitter not to want to put the best client possible out there. It never seems like a good idea not to do your best work just so someone else can. Instead, it makes sense to make third-parties aim higher, and push you — and vice versa.

Twitter may be ready to do just that with whatever this new client is.