There have been teases here and there that Google's Nexus 7 was going to get a full, official accessory treatment from ASUS, but actual details have been scarce. Consider ASUS' cover blown, almost literally. Presentation files finding their way to Nordic Hardware show the known Smart Case-like, $20 Travel Cover that's already lurking on the ASUS and Google websites, but they also spoil a leather Premium Cover that will reportedly cost $40. As for a cradle to round out the set? While