After previously stating that the Alienware Steam Machine wouldn't be customizable, Alienware has clarified that consumers can upgrade components, but the system isn't designed with that in mind:
The Alienware Steam Machine, announced at CES, is designed to deliver a great gaming experience in the living room and we will enable customers to upgrade components. Considering we've purposefully designed the Alienware Steam Machine to be smaller than the latest generation consoles, upgrading the internal components will not be as easy as compared to other platforms, such as the Alienware X51, but we will not prevent a customer from upgrading.
Does this change your opinion on their Steam Machine?