I was very disappointed by early reports (rumors) of the Fire, but the only serious issue with the actual
device is the lack of a micro-SD slot. I think this was a major mistake on Amazon's part.
We won't know for sure until the device is in our hands, but, if reports (from Amazon sources) that sideloading apk's is possible out of the box are true, it is apparently a completely standard Android 2.3.4 (Gingerbread) tablet with limited hardware (no gyroscope, no camera, no WAN, no Bluetooth, no microphone, no GPS, and no micro-SD). The Fire skin is relatively comprehensive, but it is only a skin over standard Android. If a 7" Android Gingerbread tablet makes any sense at all, then the Fire is a good baseline and the tricked out web browser might be the killer app (if it works well in practice).
To my mind the viable tablet alternatives to the Fire run Honeycomb (Android for tablets) on 7" to 9" screens, see for example from today Engadget: Archos 80 G9 review
. Bigger screens, more hardware, potentially better Android - but at a higher cost. There are obviously plenty of alternatives with a 10" screen, but I put them in a different category.