Even though the form factor is new, throw everything you know about Intel's Ultrabook concept out the window. Well, almost everything. Hewlett-Packard just unveiled its Envy 14 Spectre, a premium consumer Ultrabook coated with Gorilla Glass on the lid, display, palmrest, and HP ImagePad, and infused with a white glove treatment that includes a concierge service. Seriously.

Acer might be splitting hairs over a few millimeters here, but the company claims its new Aspire S5 Ultrabook is the thinnest the world has ever seen. The S5 is a 13.3-inch hunk of notebook that measures a scant 15mm at its thickest point and weighs less than 3 pounds. It has a magnesium-aluminum alloy cover and palmrest with a brushed metallic motif. Acer put considerable thought into the S5's appearance, molding it with "clean and ultra-fluid contours" that can be seen from all angles.

We're not out to make a mountain out of a mole hill, but it's interesting on a number of levels that a chip giant like Intel would cut down the tablet market in order to promote its own Ultrabook form factor. It's interesting because Intel doesn't typically diss on form factors, and also because the Santa Clara chip maker would love to challenge ARM on what's become its home turf, and in fact will make a serious run at slates later this year.