The big news here is the evolution of the definition of what constitutes a "tablet."
() Amazon protects its flank in the eReader market with a new floor ($79) and a premium version with improved e-ink, additional content, and a "lifetime" 3G connection in 100 countries for $149. Nobody is going to encroach on Amazon's turf in this market.
() The "Fire" is better understood as growing up from the e-Reader market than a de-featured iPad. It expands the content available from books (and to some extent magazines) to movies, videos, the web, and music. (Not clear what happens to the Kindle DX at this point; it seems to be an unwanted stepchild.)
() The "split browsing" experience, if it works, builds on the Opera model and will eliminate the one area where no one (including Apple) has been able to resolve "lags" in the user-interface, i.e. web browsing. Managing browsing to eliminate jerkiness and lags is a huge step forward for users who don't differentiate between looking at a web page and running a local app. Roadblocks and net congestion will remain but if Amazon manages to "smooth" the browsing experience, they'll impress a lot of users.
() Not clear how traditional Kindle customers will react to the backlit Fire but I suspect the expanded content available will soothe their feathers. And if it doesn't, the other new Kindle models will provide a place for them to go.
() Not sure why the Fire apparently doesn't include a built-in email or messaging client. Though an email client is apparently available for download from the Amazon digital store. No demonstration of the Fire keyboard options (that I saw) so that might be the stumbling block. (Along with the wifi only current limitation.) In any event, I think those are the missing pieces for many potential customers who don't need/want a fully featured tablet.
() All in all, Amazon is taking a step by step up the ladder approach by extending an e-reader base into "tablet" functionality. And at a price point under $200, they'll sell 'em by the boat load.
Also, leaving out 3G in their "flagship" model seems puzzling.