The promise of the ultra-cheap ultrabook hasn’t quite been fulfilled yet, but that doesn’t mean we can’t have a few sexy machines before the new ones hit. Acer’s Aspire S3 dropped yesterday, and we’ll have a review up soon, but the new Asus Zenbooks, rumored and pictured earlier but only actually announced today, are the ones I’ve been waiting for.You’ve got two basic models: the 11.6-inch UX21 and the 13-inch UX31. But there’s more, much more.