Seems like it was a huge dissappointment indeed, I haven't followed it much, but I did read PennyArcade's blog about it:
From Penny Arcade blog
Here is everything you need to understand about Home, if you should accidentally launch it from your XMB: press and hold the Playstation button in the center of your Dual-Shock or Sixaxis controller. From the menu that appears, select Quit.