“Ultrabooks” haven’t taken the computer world by storm as some pundits predicted. However. ultra-slim computer shipments will grow from 3.4 million in 2011 to 65.0 million by 2015 — a quarter of mobile shipments — according to new data from NPD DisplaySearch (www.displaysearch.com).

The research group says the mobile computer landscape is transforming from a performance-driven market to a convenience-driven market, where easy access to content and usage are the new preferred characteristics. This fundamental change in preference is most noticeable in the slowing demand for notebooks and the increasing demand for tablets.

Tablet shipments are expected to exceed notebook shipments by 2016. Notebook makers are responding by adopting the features of tablets that consumers have appreciated the most. Apple is going its own way with both the iPad and the MacBook Air (its “ultra-slim” portable). That course is working out just fine for them. The iPad dominates the tablet market, and the MacBook Air is poised to capture 39% of the slim notebook market, according to a “DigiTimes” report.

In case you’re wondering what exactly defines an ultra-slim computer, DisplaySearch says the definition is as follows: notebooks with screen sizes greater than14 inches and must have a z-height (i.e. thickness) of less than21mm, and notebooks with screen sizes less than14 inches must have a z-height of less than18mm.”

— Dennis Sellers