I've had the Kindle Fire for three days now (it showed up Tuesday, I tore into the box like it was Christmas) and I've got opinions. Some of them are even good.
Let's start with the obvious thing: $199. That price is the whole story here, and I think a lot of people are going to miss that if they walk in expecting an iPad. It's not an iPad. It's not trying to be one, no matter how much the Amazon marketing photos with the angled screen shot want you to think otherwise. This is a 7-inch, Wi-Fi-only, no-camera, no-microphone slab of glass and plastic that exists to sell you Amazon Instant Video, Kindle books, and MP3s. Once you accept that, it actually makes a lot more sense.
The hardware itself is fine. Not great, fine. It's heavier than I expected for something this size, dense in a way that feels solid in your hand but also tired your wrist out if you're holding it up reading in bed for an hour, which, guilty. The screen is a 1024x600 IPS display and it looks genuinely good for the price, colors are punchy, video looks nice. But there's only one button on the whole device (power, top edge) and no volume rocker at all, you have to pull down a software slider, which is a weird choice I keep bumping into by accident.
The software is where it gets messy
Amazon skinned Android 2.3 (Gingerbread, not the new Ice Cream Sandwich stuff that's just starting to roll out on the Galaxy Nexus) into their own Amazon-flavored interface, and you would genuinely not know this is Android under there unless someone told you. There's no app drawer in the normal sense, no home screen widgets, it's this horizontal carousel of your recent stuff plus a shelf of "favorites" underneath. It's clean. It's also kind of a cage. You're locked into the Amazon Appstore, which is still catching up to the actual Android Market in terms of selection, and there's no way to get to Google's app store without rooting the thing, which people are already figuring out how to do about four minutes after launch.
The browser, Amazon calls it Silk, is the part I was most curious about, and it's the part that's let me down the most. The pitch is that it does some of its rendering work on Amazon's servers ("cloud acceleration," supposedly using EC2) so pages load faster. In practice I'm not convinced I can tell the difference, and a couple times it felt slower than my phone's browser, especially the first load of a page before whatever caching kicks in. Tab switching has a stutter to it. Text reflow when you pinch zoom is laggy enough that I noticed it within the first ten minutes, and once you notice something like that you can't stop noticing it. It's not broken, I want to be clear, it's just not the leap forward the pre-launch write-ups made it sound like.
Battery life has been decent, I'm getting through a full day of casual reading and some video without a charge, though obviously nowhere near what a Kindle e-ink device gives you (my old Kindle 3 laughs at all of this).
Here's my actual take: this isn't an iPad competitor, this is a Nook Color competitor, and against the Nook Color it's a pretty clear win, mostly because of what's sitting behind it. The Fire's whole reason for existing is Amazon Prime. If you're already paying for Prime, or you buy a lot of Kindle books, or you're the kind of household that streams a lot of stuff, $199 is basically an impulse buy that plugs directly into a library you already own. My in-laws, who own zero Apple products and have exactly one streaming habit (Prime video, every night, without fail), are getting more genuine use out of this thing in three days than I expected. For someone who wants a general-purpose tablet to do email and games and browse and take the occasional photo of their kid, save up the extra money and get something else, because that's not this device's job and it's honestly a little annoying when the software tries to pretend otherwise.
Worth the price. Worth being skeptical of the marketing around it. Two things that are both true at once, apparently.