It's now been almost a year since the Kindle Fire HD was released, and as surely as fall follows summer, Amazon is preparing to launch an updated line of tablets to compete against the rejuvenated Nexus 7 and the (assumed) iPad Mini with Retina display. According to "trusted sources," Amazon will be releasing new versions of the 7- and 8.9-inch Kindle Fire HD and the entry-level Kindle Fire in September -- and, if the trusted source is to be believed, the Kindle Fire HDs will come with very impressive hardware specs indeed.