Generally liking it, but I have to admit my major objection to it right now is that there's no Google. This means you can't, for example, install software you legitimately bought on the Android Market, unless you buy it a second time on the Amazon App Store. Not good.
Also meant I had to do some fancy sideloading to get Google Music installed - as Google Music has my entire music library, and Amazon Cloud doesn't (maybe the latter would if it (a) supported more formats and (b) had an automatic Ubuntu uploader like Google Music does.) And what's with it only having 6G of storage? Where did that come from?
Plusses - perfect size, not too big (I've used 10" tablets before - they're not portable and anyone who tells you otherwise is a fanboi), not too small; UI is pretty decent for the most part. Battery life seems to be excellent, better than my Android phone indeed.
I'm thinking though it's highly likely that the rumored CyanogenMod 9 version for Kindle Fire (that's Icecream Sandwich) will end up on mine, simply because I can't do without teh Google, and quite honestly, I trust Google more than I trust Amazon as far as giant faceless corporations go.