Facebook has just sent out an invite to press announcing an event Thursday, April 4th at its headquarters in Menlo Park California that appears to be related to Android. Some possibilities include a re-write of its Android app, a heavily modified Android OS or even its own hardware.

The last event that Facebook held at its HQ was to introduce its new News Feed, you can read about those announcements here. We also took a deeper dive into the updates to the site’s longest-running unchanged feature and found a mostly successful bit of shuffling going on. Those changes, though limited to the version on the web, were mobile-focused in many ways.

In fact, Facebook stated at the event that it tried very hard to keep it consistent with the mobile vision that it had for itself. The design of the new News Feed and sidebar menu, for example, resemble nothing less than the iPad version of the app. But apps are all floating on top of the operating system layer, which poses an issue for Facebook, which does not own the gatekeepers to its eyeballs. There are now more than 600 million monthly active users of its mobile apps, and it would behoove it to create a direct channel to those viewers.

Screen Shot 2013 03 28 at 5.04.27 PM Facebook holds event to show off its new home on Android, re igniting buzz of its own phone or OS

And that’s why the other persistent rumor has been that Facebook is going to make its ‘own phone’, or a phone with Facebook so embedded in the OS that you can’t really tell the difference. There have been a couple of devices with a Facebook button on their faces, making posting easy, but a true ‘Facebook phone’ would have the network’s various properties threaded throughout its structure.

That being said, a specialized operating system with Facebook everywhere inside seems like it would best serve as a service layer for the developing market, rather than a whole new OS for the first world. But Facebook wouldn’t be the first one to do it, as Amazon has created its own offshoot of Google’s Android OS as well. Specs for a purported Facebook phone with HTC hardware were leaked in early March and they look roughly on par with devices from other manufacturers. Techcrunch is saying that this announcement will be about the operating system on the device and 9t05Mac chimes in with the news that an ad campaign is in the works for it. If an HTC device arrives, it would be the culmination of nearly a year of rumored collaboration between Facebook and the device maker.

Whether this announcement is about a Facebook-infested device or a refresh to its Android app, we’ll be there to cover it.

Image Credit: JOEL SAGET/AFP/Getty Images