The just announced Acer S5 Ultrabook kicks off the new ultrabook genre that manufacturers are going to push at CES. It’s 13.3-incher that checks in at under 3 pounds, is 15mm thin, offering Instant On functionality, a magnesium-aluminum alloy cover (in Onyx Black), HDMI / USB 3.0 / Thunderbolt (!!!) ports and an SSD for good measure. It will ship in Q2 of 2012, and that’s all we know about it, at the moment. PR after the jump.