A little further investigation of the Zonbu service.....
Cost of Laptop = $249 with 2yr agreement @ $14.95 -- that equates to a $609 commitment
Cost of Laptop = $479 with month-to-month @ $14.95 -- with the 2 yr commit, you basically will spend $130 extra for the same two year period
Software is all Open Source and has all the required stuff -- now if a kid was the target for this laptop (go ahead and get one for Christmas why don't ya) - then the only real drawback would be "self installed" games that require the windows operating system or those games that require an installation of a local version that are only Windows based (but I would assume many will move to supporting both Apple and Linux, based upon the market acceptance of both operating systems and they primary target audience). But, if you have kids (or adults) that play online games that don't require a download (for my oldest son that includes RuneScape) - there would be no difference using this laptop.
What is interesting is the "control" of the applications - they are preinstalled, updated automatically and NO, you can't install your own applications. That's how they get away with the support costs - preconfigured and closed - only a small number of applications - so there is a finite numbers of questions that can be asked. Another interesting thing is that they don't actually come out and say they are using Linux (see their applications FAQ).