Some of the blockers for mainstream Linux desktop usage are lack of legal codecs, hardware integration and certain types of basic functionality like software suspend not working reliably. This is not news, of course, but rather the typical gripes people have had for years. Even as much of the Free software has reached the point of being true-blue entries in the top echelons of functionality and quality, some of these issues continue to nag at us unanswered.
These are things that the KDE community itself can't really fix, at least not by simply writing KDE-based software. I always figured, and said as much whenever the topic came up, that eventually Linux would be shipped by system integrators who would invest in an "OEM" version of a Linux-based OS. They would take (or so I thought anyways) a distribution that already exists and has commercial support behind it and do much as they do with Windows and gussy it up for their combined hardware/software offering. At this point in the product chain consumers are forking out hard currency for product (the computer) and there is some profit margin in there, helped along by the lack of a Windows license (hopefully, anyways =). This money could be used to purchase the needed bits, such as codecs and fonts. By adding just a little bit of "final primping" Linux would finally be a complete product. Instead people want a system with a lower price point and the cool feeling that comes from seeing Linux being an option on a system integrator's website.
So when Dell announced that they were going to be shipping Linux laptops and the Canonical marketing powerhouse started cranking out the stories about it, I figured this could be the start of this development. Unfortunately, someone (Canonical?) forgot to tell Dell (or they just didn't listen?) that more than simply slapping Ubuntu on a laptop was needed. The result has been that reviews from the likes of the Wall Street Journal are starting to appear and they have not been particularly flattering, even going so far as to warn people away from Linux and Ubuntu.