There are other business-related limitations: The mail app supports GMail, Yahoo, Hotmail, AOL, POP3 and IMAP, but no Exchange or even Google Apps. There are third-party apps in the Amazon store to do Exchange, but it's already starting to get complicated. There does not appear to be a Google Gmail app. For my own Google Apps domain I had to use the Kindle browser, which was a pretty good experience except for some bugs I encountered. Call it version 1.0 stuff.
Considering the important apps it's missing, it's all the more remarkable that the Amazon app store includes apps that the Kindle Fire can't support. There are, for example, several apps that request access to the camera. Of course, the Fire has no camera. But the app installs without objection, indicating that the Android fork is ignoring or agreeing to permission requests from apps that the device cannot support. On one such app I tested I got to the point of loading an image from the camera and then the app crashed.
Incidentally, the Fire's Device Settings page has an option, which you'll find in Android normally, to allow the installation of apps from untrusted sources. On iPhones they call this jailbreaking. It's not clear how you'd install untrusted apps after you select this option, but it could be one way to get around Amazon's restrictions.
This Enhanced Kindle Edition book should have video, but it's not supported on the Fire, just on iOS.
I have had a second-generation Kindle (what they're now calling the Kindle Keyboard) for some time and I love it. It's light, cheap, and primitive technologically. But in terms of reading books the biggest difference between it and the Fire is the back-lit screen on the Fire and the reflective screen on the older Kindle. With adequate light, even with excessive light, the old Kindle is as crisp as a printed sheet of paper, and the battery can literally last weeks between charges. Of course, reading is all it's good for and the Fire does so much more.
One problem I experienced which brought home for me just how unbaked the Kindle Fire experience is was a book I bought for it: "Berlin 1961 Amplified (Enhanced Edition) [Kindle Edition With Audio/Video]". I just went ahead and made the stupid assumption that I'd see the audio and video on my Kindle Fire, but no. It never worked (which meant instead of seeing a clip of Nixon and Khrushchev debating, all I got was a still). Only later did I notice on the product page "Audio/Video content only available for iPads, iPhones, and iPod Touch devices."
I really want to say that all the problems don't matter and that for $200 the Fire is a good deal. I was ready to fork over my own $200. But the problems that bother me most, such as the lack of support for audio and video in books, strike me as ones that will get fixed with a little time. So I think it's worth holding off, at least for me. If you need something for the holidays, maybe it's worth buying on the assumption that the fixes can all be made in software. And if you're looking for a tablet for business, look elsewhere.