Is Google cooking up an updated Nexus 10 in conjunction with Samsung? Sources say yes, and go one step further, claiming the new tablet is already making the rounds wearing the case of the original Nexus 10. Bright Side of News says the prototype model was sneaking around the back halls of CES and could again make a covert appearance at MWC before a grand unveiling at Google I/O.

So what’s new in the rumored second-gen Nexus 10? A quad-core CPU with 8-core Mali-T678 graphics, an upgrade from the dual-core Exynos 5 found in the first iteration. According to the initial report, the folks at Bright Side of News were able to take the tablet for a test drive and benchmarks proved to be “night and day” by comparison.

Making thing a little more interesting, the rumor immediately called us back to a story from earlier today detailing new tablet models from Samsung. One in particular, codenamed Roma and carrying model number GT-P8200, appears lined up as the successor to the Nexus 10, which carries the model number GT-P8110. While talk of a quad-core version of the slate is strictly rumor at this point, the existence of this Roma tablet creates a good deal of intrigue.

If a quad-core model proves to be in development, don’t expect it to launch any time soon. Google reportedly plans to launch the device closer to the back-to-school fall season.

[via DroidLife]