Is Microsoft already working on the developer kits for its Xbox successor... or a slimmed-down version of the Xbox 360?

Had one a nickel for every Xbox 720 rumor that hit the airwaves well in advance of the console's alleged 2013 release date (there's $0.05 more), you could probably buy enough gear to make your own next-generation console.

Here's another log to throw in the rumor fire: According to IGN, who spoke to undisclosed sources to unearth this one, the Xbox 720  or whatever the name of Microsoft's Xbox 360 successor happens to be  is allegedly already being manufactured at a plant in Texas.

Flextronics is supposedly behind the manufacturing and testing of the new Xbox. That's the same company that built Microsoft's original Xbox and the Xbox 360, as well as Microsoft's Zune digital media player.

But is this new Flextronics-built Xbox going to be the one that ends up in your living room by the end of the year? Nope.

"The most likely case here is that new manufactured hardware would be development kits, consoles created specifically so game designers know what they're working with," writes IGN's Mitch Dyer. "Microsoft said flat-out it wasn't debuting a new console at E3, so rumors regarding new manufactured boxes probably wouldn't stack up to a reveal."

In other words, don't list your Xbox 360 on eBay just yet.

But what if the rumored console that Flextronics is building isn't the next-generation Xbox at all? Microsoft's response to the rumors has some industry-watchers buzzing that the console being manufactured down in Texas isn't the new Xbox but, rather, a slimmed-down variant of the preexisting Xbox 360.

"Xbox 360 has found new ways to extend its lifecycle like introducing the world to controller-free experiences with Kinect and re-inventing the console with a new dashboard and new entertainment content partnerships. We are always thinking about what is next for our platform and how to continue to defy the lifecycle convention. Beyond that we do not comment on rumors or speculation," said Microsoft in a statement to IGN.

Microsoft's quick mention of Xbox lifecycles in relation to rumors about Xbox manufacturing could be a head-nod to the "Xbox Lite" console that's also alleged to be in the works. The trimmed-down system is rumored to eschew an optical drive in favor of Xbox Live-based streaming and downloading, but it's unclear whether the system's rumored ARM-based processor would be geared for just arcade games and movie streaming or whether it would be able to run more robust Xbox 360 titles as well.

For more tech tidbits from David Murphy, follow him on Facebook or Twitter (@thedavidmurphy).