Amazon seems to have taken the negative reviews to heart because there's an update available for the Kindle Fire HD the day it got into consumer hands. It looks to be pretty hefty update and weighs in at over 400MB. Amazon hasn't said what's in it, but clearly it contains some significant changes to the software.
The second gen Kindle Fire also got an update today, and you can find both updates at Amazon. The KFHD update is numbered 7.1.5, and Amazon says that they will be pushing it out to all KFHD over the next few days.
So my new Kindle Fire HD has been out of the box for less than an hour and there's already an update. I'm pointing that out not to compliment Amazon for their service but to criticize them for not waiting to release a more finished device. I hate wasting my time doing Amazon's service work as an unpaid tech.