I just bought and set up the Alienware Alpha i7 today, and I am having a number of issues with it.  I'll keep this post to just one.

My Xbox wireless controller (included with the Alpha i7 and using the brand new Duracell batteries from the box) seems to be experiencing intermittent connectivity issues.  When navigating the menus in Steam or the Alpha UI, my button pushes will register just fine for about 5 seconds, then nothing I input will register for a few seconds, then they will resume registering normally.  This is a constant phenomenon.  I get a few seconds of working perfectly, followed by a few seconds of nothing registering at all, rinse, repeat ad infinitum.  This is not a latency issue, as nothing I input during the "dead period" subsequently registers.  It seems far too regular to be a signal issue, but I suppose my technical knowledge is not sufficient to rule it out.  I have tried bringing the wireless receiver closer to the couch where I am sitting (full extent of the cord provided puts it about 2-3 feet from where I am holding the controller), but there is no perceptible difference.