Samsung has already sent out the teasers regarding its mystery device reveal later this month, expected to be an 8.9-inch version of the Galaxy Tab Android tablet. Now another sliver of the slate has been shown, this time complete with what looks to be the tablet’s 3.5mm headphone socket, and it certainly appears to be thin.

The extra bowing around the headphone socket implies that the slate as a whole is little more than the width of that port. That could potentially make it thinner than the original 7-inch Galaxy Tab (which was 0.47-inches thick) and a decent rival to the waifish iPad 2.

The full reveal is expected on March 22, and we’re guessing we’ll see a tweener-slate fitting in between the original Tab and the newer 10.1-inch model announced last month. Android 3.0 Honeycomb seems likely too, along with a dual-core processor.

[Thanks to everyone who sent this in!]