For years, Microsoft proponents have been telling Apple proponents that we pay far too much for Mac OS X on the same hardware as Microsoft OEM hardware.
I believe much like the iPad market (referred to as the "tablet market" by many) that there isn't a significant "ultraportable market" outside Apple MacBook Air.
I believe the Apple "ultraportable" (MacBook Air) market is strong for the following reasons:
Mac OS X (Aqua ui, accessibility, layered frameworks architecture, reliability, security, technology innovation (Bluetooth 4.0, Thunderbolt as recent examples)
Best in Class Customer Service
iLife (GarageBand, iMovie, iPhoto, Mac App Store)
iCloud (iTunes in the Cloud, PhotoStream, Documents in the Cloud, Apps, Books and Backup, Calendar, Mail and Conacts, Find my Friends and Find my iPhone)
iTunes integration (market-leading ecosystem for apps, books, music, movies, podcasts, TV shows which allow me to use many of these products and services on (m)any Apple device(s)
In other words, as far as I can discern, Apple is the only vendor whose primary focus is the user experience. Microsoft OEMs are far too busy differentiating themselves with hardware specifications because they don't understand the user experience. Amazon provides a comparable experience to iTunes and (some of) iCloud via Amazon Cloud but doesn't provide mail, calendars or contacts (AFAIK). Google provides a cloud for Google Apps (Gmail, Google Groups, Google Calendar, Talk, Docs and Sites) but lacks iTunes media content.
iTunes media content provides an immediate, manifest justification for Apple products and services while iCloud extends the products and services across the entire Apple product line. Unless other vendors understand these principles behind the success of Apple's premium products and services as well as the advantages of Apple Stores providing local services and support they won't succeed.