Pentax has just announced a new series of top-of-the-line, premium digital-only lenses called DA* (say "dee-ay-star"). The first two DA* lenses are constant-aperture ƒ/2.8 zooms with focal lengths of 16–50mm (above) (roughly 25–75mm equivalent) and 50–135mm (left) (roughly 75–210 equivalent). They bring together aspherical elements, special optical-glass elements, and original lens coatings, and are designed to cover just the area of a digital sensor. Both lenses have 9-blade apertures and impressively short close-focus distances (.3 and 1 meters respectively). Pentax promises the new DA* lenses will be "superior to any existing lens series in terms of contrast, clarity and edge-to-edge sharpness."
The lenses boast an impressive array of special features. On the K10D they have near-silent "Supersonic" SDM focusing (similar to Canon's USM), but can also be used on older bodies that have focusing motors built into the bodies; full-time manual focus override that works on both body types; and they are heavily sealed and water- and dust-resistant, to match the weather-sealed K10 body—and this includes a special, super-hard fluorine vapor-deposited coating on the outermost element that repels dust, moisture, grease, and dirt.
I gotta say I am excited about the new lens from Pentax, it would be a perfect walk around travel lens for me.