"As of the time of this review high quality zoom lens options are not really available in Sony E mount (Sony NEX) so it is viable to have a look beyond. Sony Alpha (DSLR) lenses can be used on NEX cameras via Sony Alpha adapters (EA-LA1 & LA2). The more interesting adapter is the new Sony EA-LA2 which basically transforms your NEX into a Sony Alpha SLT DSLR with phase-detection AF support - with no real drawbacks apart from the extra bulk.
An attractive Alpha lens option is certainly the fairly new Sony 16-50mm f/2.8 DT SSM - a fast, high grade standard zoom. It is a native APS-C format lens featuring a field-of-view equivalent to about "24-75mm f/4" on full format cameras. The "f/4" refers to the comparable depth-of-field. For determining the exposure, the real aperture obviously remains the relevant number. It is a rather large lens so a NEX camera looks a little dwarfish when "attached to the lens""